Building Performance Knowledge Community

The "Details Forum" is a major project in 2019 of the Building Performance Knowledge Community (BP-KC).

The objective is to provide online information that shares good details among architects via a web location within the BP-KC site.  Another focus is to provide a vehicle for publicizing the activities of technically-oriented architects.

A draft detail of a Parapet has been prepared as a test case for implementing a first draft of the "Details Forum." 
See the attachment. 

Stay tuned for this first draft to be published soon.

Project participants are:

------------------------------
Joseph Deringer AIA
Institute for Sustainable Performance of Buildings
Berkeley CA
------------------------------

Original Message------

The "Details Forum" is a major project in 2019 of the Building Performance Knowledge Community (BP-KC).

The objective is to provide online information that shares good details among architects via a web location within the BP-KC site.  Another focus is to provide a vehicle for publicizing the activities of technically-oriented architects.

A draft detail of a Parapet has been prepared as a test case for implementing a first draft of the "Details Forum." 
See the attachment. 

Stay tuned for this first draft to be published soon.

Project participants are:

Brad Gellert (lead)

Stephen Katz

Drake Wauters

------------------------------
Joseph Deringer AIA
Institute for Sustainable Performance of Buildings
Berkeley CA
------------------------------

Original Message------

Thanks for the message about the start of the Details Forum. What a great idea. And an excellent example as the inaugural article about parapet thermal performance. Thanks to Payette for sharing their research and analysis. Very thoughtful way to address a common issue. We have had concerns about building a parapet on top insulation, perhaps crushing the insulation material and reducing its effectiveness. However, the simple approach of inserting insulation within the framing at the level of the roof insulation is a good approach. Thanks, again.

Sherman Aronson

Sherman C. Aronson, AIA, LEED AP BD+C Senior Associate

1216 Arch Street Philadelphia,  PA   19107‑2835 Tel: 215 563 3900 Ext: 124 www.BLTa.com

NOTICE THIS E-MAIL, INCLUDING ANY ATTACHMENTS, IS CONFIDENTIAL AND FOR THE INTENDED RECIPIENT ONLY. IT MAY BE LEGALLY PRIVILEGED AND PROTECTED FROM DISCLOSURE. NOTHING IN THIS E-MAIL GRANTS ANY LICENSE OR TRANSFERS ANY OWNERSHIP OR ANY INTELLECTUAL PROPERTY RIGHTS TO THE RECIPIENT. IF THE READER OF THIS MESSAGE IS NOT THE INTENDED RECIPIENT, YOU ARE INFORMED THAT ANY DISSEMINATION, COPYING OR DISCLOSURE OF THE MATERIAL CONTAINED HEREIN, IN WHOLE OR IN PART, IS STRICTLY PROHIBITED. IF YOU HAVE RECEIVED THIS INFORMATION IN ERROR, OR ARE NOT THE INTENDED RECIPIENT, PLEASE NOTIFY THE SENDER IMMEDIATELY AND PURGE THIS MESSAGE. INTERNET COMMUNICATIONS CANNOT BE GUARANTEED TO BE SECURE, VIRUS-FREE OR ERROR FREE. BLT ARCHITECTS ACCEPTS NO LIABILITY FOR ANY LOSS OR DAMAGE FROM THE USE OF THIS E-MAIL.

We have done them. The American Society of Civil Engineers has a "Design and Construction of Frost-Protected Shallow Foundations". See attached. Your air freezing index is probably similar to mine. I recommend a civil or structural engineer for the foundation design.

------------------------------
Mike Sealander AIA
Sealander Studio
Brooklin ME
------------------------------

Original Message:
Sent: 05-16-2019 07:43
From: William DeVos
Subject: "Details Forum"

I have a retail client interested in trying frost protected shallow foundations for their stores.  Can anyone tell me of someone who does them regularly so we can learn from them and develop some confidence?

William J. DeVos
APD Engineering and Architecture
237 Rockingham Street
Rochester, NY   14620
(585) 435-0364
<rflbilldevos@gmail.com>

Original Message------

Thanks for the message about the start of the Details Forum. What a great idea. And an excellent example as the inaugural article about parapet thermal performance. Thanks to Payette for sharing their research and analysis. Very thoughtful way to address a common issue. We have had concerns about building a parapet on top insulation, perhaps crushing the insulation material and reducing its effectiveness. However, the simple approach of inserting insulation within the framing at the level of the roof insulation is a good approach. Thanks, again.

Sherman Aronson

Sherman C. Aronson, AIA, LEED AP BD+C Senior Associate

1216 Arch Street Philadelphia,  PA   19107‑2835 Tel: 215 563 3900 Ext: 124 www.BLTa.com

NOTICE THIS E-MAIL, INCLUDING ANY ATTACHMENTS, IS CONFIDENTIAL AND FOR THE INTENDED RECIPIENT ONLY. IT MAY BE LEGALLY PRIVILEGED AND PROTECTED FROM DISCLOSURE. NOTHING IN THIS E-MAIL GRANTS ANY LICENSE OR TRANSFERS ANY OWNERSHIP OR ANY INTELLECTUAL PROPERTY RIGHTS TO THE RECIPIENT. IF THE READER OF THIS MESSAGE IS NOT THE INTENDED RECIPIENT, YOU ARE INFORMED THAT ANY DISSEMINATION, COPYING OR DISCLOSURE OF THE MATERIAL CONTAINED HEREIN, IN WHOLE OR IN PART, IS STRICTLY PROHIBITED. IF YOU HAVE RECEIVED THIS INFORMATION IN ERROR, OR ARE NOT THE INTENDED RECIPIENT, PLEASE NOTIFY THE SENDER IMMEDIATELY AND PURGE THIS MESSAGE. INTERNET COMMUNICATIONS CANNOT BE GUARANTEED TO BE SECURE, VIRUS-FREE OR ERROR FREE. BLT ARCHITECTS ACCEPTS NO LIABILITY FOR ANY LOSS OR DAMAGE FROM THE USE OF THIS E-MAIL.

Original Message------

We have done them. The American Society of Civil Engineers has a "Design and Construction of Frost-Protected Shallow Foundations". See attached. Your air freezing index is probably similar to mine. I recommend a civil or structural engineer for the foundation design.

------------------------------
Mike Sealander AIA
Sealander Studio
Brooklin ME
------------------------------

​I did this one time for an exterior application that needed frost protection but had too many buried utilities on the site. It worked. It is a very interesting concept that should work.

Our neighbors to the north are the experts in this area I believe. Perhaps it would be useful to contact the Canadians.

------------------------------
Paul Johnson FAIA
SmithGroup
Detroit MI
------------------------------

Original Message:
Sent: 05-16-2019 07:43
From: William DeVos
Subject: "Details Forum"

I have a retail client interested in trying frost protected shallow foundations for their stores.  Can anyone tell me of someone who does them regularly so we can learn from them and develop some confidence?

William J. DeVos
APD Engineering and Architecture
237 Rockingham Street
Rochester, NY   14620
(585) 435-0364
<rflbilldevos@gmail.com>

Original Message------

Thanks for the message about the start of the Details Forum. What a great idea. And an excellent example as the inaugural article about parapet thermal performance. Thanks to Payette for sharing their research and analysis. Very thoughtful way to address a common issue. We have had concerns about building a parapet on top insulation, perhaps crushing the insulation material and reducing its effectiveness. However, the simple approach of inserting insulation within the framing at the level of the roof insulation is a good approach. Thanks, again.

Sherman Aronson

Sherman C. Aronson, AIA, LEED AP BD+C Senior Associate

1216 Arch Street Philadelphia,  PA   19107‑2835 Tel: 215 563 3900 Ext: 124 www.BLTa.com

NOTICE THIS E-MAIL, INCLUDING ANY ATTACHMENTS, IS CONFIDENTIAL AND FOR THE INTENDED RECIPIENT ONLY. IT MAY BE LEGALLY PRIVILEGED AND PROTECTED FROM DISCLOSURE. NOTHING IN THIS E-MAIL GRANTS ANY LICENSE OR TRANSFERS ANY OWNERSHIP OR ANY INTELLECTUAL PROPERTY RIGHTS TO THE RECIPIENT. IF THE READER OF THIS MESSAGE IS NOT THE INTENDED RECIPIENT, YOU ARE INFORMED THAT ANY DISSEMINATION, COPYING OR DISCLOSURE OF THE MATERIAL CONTAINED HEREIN, IN WHOLE OR IN PART, IS STRICTLY PROHIBITED. IF YOU HAVE RECEIVED THIS INFORMATION IN ERROR, OR ARE NOT THE INTENDED RECIPIENT, PLEASE NOTIFY THE SENDER IMMEDIATELY AND PURGE THIS MESSAGE. INTERNET COMMUNICATIONS CANNOT BE GUARANTEED TO BE SECURE, VIRUS-FREE OR ERROR FREE. BLT ARCHITECTS ACCEPTS NO LIABILITY FOR ANY LOSS OR DAMAGE FROM THE USE OF THIS E-MAIL.

Original Message------

​I did this one time for an exterior application that needed frost protection but had too many buried utilities on the site. It worked. It is a very interesting concept that should work.

Our neighbors to the north are the experts in this area I believe. Perhaps it would be useful to contact the Canadians.

------------------------------
Paul Johnson FAIA
SmithGroup
Detroit MI
------------------------------

I think a Section here on building details is a great idea and the parapet, a very common problem area, is a perfect place to start.  The details presented compare two routes for the thermal barrier to follow at the parapet.  The discussion suggests that short-cutting the thermal barrier across the base of the parapet will have the advantage of reducing the total surface area of heat-transmitting wall exposed to the exterior. The proposed thermal shortcut uses spray foam inserted between the metal studs.  Some things to consider:

1.     The vertical studs penetrate the spray foam so the R-value of the foam has to be de-rated accordingly.

2.     To place the spray foam as shown would require a horizontal sheet "backer" closing off the space between studs.  The detail does not show what the backer material might be or how it would be held in place.  Often, vertical studs are doubled around openings and close-packed at corners multiplying the labor and practical problems of placing the backer and the foam.

3.     Placing the spray foam: Is it placed from below via long nozzle inserted up behind the beam?  Installers have told us this is not practical.  Placed from above before the parapet is sheathed?  This can create construction sequence issues.

4.     But the most unpredictable risk is the possibility of condensation forming in the un-vented, un-tempered, space above the foam.

The discussion assumes the necessity of a parapet.  If optimum thermal performance is a goal, then early design discussions should question this necessity.

------------------------------
Alan Swift AIA
Director, Design Integration
dbHMS Design Build Engineering
Chicago IL
------------------------------

Original Message:
Sent: 05-12-2019 17:26
From: Joseph Deringer
Subject: "Details Forum"

The "Details Forum" is a major project in 2019 of the Building Performance Knowledge Community (BP-KC).

The objective is to provide online information that shares good details among architects via a web location within the BP-KC site.  Another focus is to provide a vehicle for publicizing the activities of technically-oriented architects.

A draft detail of a Parapet has been prepared as a test case for implementing a first draft of the "Details Forum."
See the attachment.

Stay tuned for this first draft to be published soon.

Project participants are:

Brad Gellert (lead)

Stephen Katz

Drake Wauters

------------------------------
Joseph Deringer AIA
Institute for Sustainable Performance of Buildings
Berkeley CA
------------------------------

Hi everyone, this is a great discussion one which I can help with feedback. I rarely build these days, I was/am a licensed builder with a carpentry trade background, so I have a bit of an idea what's going on.
 I am in Australia and I know that a lot of our building regulations and methodologies overlap, so I thought it may be of some interest to see a few details that I created. I do all of my details in 3D, I actually animate them in Sketchup so our subcontractors get it right the first time. Here is an example https://3dlibrary.rubysketch.com/entries/pronto-panel-3d-residential-detail

------------------------------
Andrew Dwight
Designer/BIM manager AAD Build
Sydney Australia
------------------------------

Original Message:
Sent: 05-24-2019 12:10
From: Alan Swift
Subject: "Details Forum"

I think a Section here on building details is a great idea and the parapet, a very common problem area, is a perfect place to start.  The details presented compare two routes for the thermal barrier to follow at the parapet.  The discussion suggests that short-cutting the thermal barrier across the base of the parapet will have the advantage of reducing the total surface area of heat-transmitting wall exposed to the exterior. The proposed thermal shortcut uses spray foam inserted between the metal studs.  Some things to consider:

1.     The vertical studs penetrate the spray foam so the R-value of the foam has to be de-rated accordingly.

2.     To place the spray foam as shown would require a horizontal sheet "backer" closing off the space between studs.  The detail does not show what the backer material might be or how it would be held in place.  Often, vertical studs are doubled around openings and close-packed at corners multiplying the labor and practical problems of placing the backer and the foam.

3.     Placing the spray foam: Is it placed from below via long nozzle inserted up behind the beam?  Installers have told us this is not practical.  Placed from above before the parapet is sheathed?  This can create construction sequence issues.

4.     But the most unpredictable risk is the possibility of condensation forming in the un-vented, un-tempered, space above the foam.

The discussion assumes the necessity of a parapet.  If optimum thermal performance is a goal, then early design discussions should question this necessity.

------------------------------
Alan Swift AIA
Director, Design Integration
dbHMS Design Build Engineering
Chicago IL

Original Message:
Sent: 05-12-2019 17:26
From: Joseph Deringer
Subject: "Details Forum"

The "Details Forum" is a major project in 2019 of the Building Performance Knowledge Community (BP-KC).

The objective is to provide online information that shares good details among architects via a web location within the BP-KC site.  Another focus is to provide a vehicle for publicizing the activities of technically-oriented architects.

A draft detail of a Parapet has been prepared as a test case for implementing a first draft of the "Details Forum."
See the attachment.

Stay tuned for this first draft to be published soon.

Project participants are:

Brad Gellert (lead)

Stephen Katz

Drake Wauters

------------------------------
Joseph Deringer AIA
Institute for Sustainable Performance of Buildings
Berkeley CA
------------------------------

Hi Alan,  
Thanks for the great comments you seem to be the only person in this discussion who noticed the condensation issue, so I'll direct my response to you (though it would be nice if others addressed the topic of the OP).  The detail attachment file stated that "The question with the non-Dow details, is there a danger of condensation occurring in the cavity in the parapet wall above the insulation level?"  It looks to me like the non-Dow detail has an unlabeled layer of 5/8" thick sheathing material continuous on back side of the parapet.  That looks like a potential path for vapor transmission into the cavity.  Do you think it would help to break the continuity of the layer like they do in the Dow detail?

------------------------------
Richard Linsky AIA
Project Architect
Jacobs/Wyper Architects, LLP
Springfield PA
------------------------------

Original Message:
Sent: 05-24-2019 12:10
From: Alan Swift
Subject: "Details Forum"

I think a Section here on building details is a great idea and the parapet, a very common problem area, is a perfect place to start.  The details presented compare two routes for the thermal barrier to follow at the parapet.  The discussion suggests that short-cutting the thermal barrier across the base of the parapet will have the advantage of reducing the total surface area of heat-transmitting wall exposed to the exterior. The proposed thermal shortcut uses spray foam inserted between the metal studs.  Some things to consider:

1.     The vertical studs penetrate the spray foam so the R-value of the foam has to be de-rated accordingly.

2.     To place the spray foam as shown would require a horizontal sheet "backer" closing off the space between studs.  The detail does not show what the backer material might be or how it would be held in place.  Often, vertical studs are doubled around openings and close-packed at corners multiplying the labor and practical problems of placing the backer and the foam.

3.     Placing the spray foam: Is it placed from below via long nozzle inserted up behind the beam?  Installers have told us this is not practical.  Placed from above before the parapet is sheathed?  This can create construction sequence issues.

4.     But the most unpredictable risk is the possibility of condensation forming in the un-vented, un-tempered, space above the foam.

The discussion assumes the necessity of a parapet.  If optimum thermal performance is a goal, then early design discussions should question this necessity.

------------------------------
Alan Swift AIA
Director, Design Integration
dbHMS Design Build Engineering
Chicago IL

Original Message:
Sent: 05-12-2019 17:26
From: Joseph Deringer
Subject: "Details Forum"

The "Details Forum" is a major project in 2019 of the Building Performance Knowledge Community (BP-KC).

The objective is to provide online information that shares good details among architects via a web location within the BP-KC site.  Another focus is to provide a vehicle for publicizing the activities of technically-oriented architects.

A draft detail of a Parapet has been prepared as a test case for implementing a first draft of the "Details Forum."
See the attachment.

Stay tuned for this first draft to be published soon.

Project participants are:

Brad Gellert (lead)

Stephen Katz

Drake Wauters

------------------------------
Joseph Deringer AIA
Institute for Sustainable Performance of Buildings
Berkeley CA
------------------------------

The idea of sharing and discussing details is great!

I do have another comment on the parapet details: I do not find a clear indication of the continuity of the air barrier on these details.  Certainly, making sure we have continuous thermal insulation is important, but if there is air leakage at the roof/wall intersection, then the thermal barrier is compromised and moist air will condense where we don't want it.  

• For the wall, spay foam insulation can serve as an air barrier, but how does it transition to membranes?  What happens when we use rigid foam insulation boards instead of the spray foam?
• For the roof, do we want the single-ply membrane to serve as the air barrier, or are we using a air/vapor retarder membrane below the roof insulation to serve this purpose?  In either case, how are penetrations sealed?
• And then, how does the roof air barrier meet the wall air barrier?

------------------------------
Margaretha Eckhardt AIA, CSI, CCS, LEED AP
Payette Associates, Inc.
Boston MA
------------------------------

Original Message:
Sent: 06-04-2019 21:53
From: Richard Linsky
Subject: "Details Forum"

Hi Alan,
Thanks for the great comments you seem to be the only person in this discussion who noticed the condensation issue, so I'll direct my response to you (though it would be nice if others addressed the topic of the OP).  The detail attachment file stated that "The question with the non-Dow details, is there a danger of condensation occurring in the cavity in the parapet wall above the insulation level?"  It looks to me like the non-Dow detail has an unlabeled layer of 5/8" thick sheathing material continuous on back side of the parapet.  That looks like a potential path for vapor transmission into the cavity.  Do you think it would help to break the continuity of the layer like they do in the Dow detail?

------------------------------
Richard Linsky AIA
Project Architect
Jacobs/Wyper Architects, LLP
Springfield PA

Original Message:
Sent: 05-24-2019 12:10
From: Alan Swift
Subject: "Details Forum"

I think a Section here on building details is a great idea and the parapet, a very common problem area, is a perfect place to start.  The details presented compare two routes for the thermal barrier to follow at the parapet.  The discussion suggests that short-cutting the thermal barrier across the base of the parapet will have the advantage of reducing the total surface area of heat-transmitting wall exposed to the exterior. The proposed thermal shortcut uses spray foam inserted between the metal studs.  Some things to consider:

1.     The vertical studs penetrate the spray foam so the R-value of the foam has to be de-rated accordingly.

2.     To place the spray foam as shown would require a horizontal sheet "backer" closing off the space between studs.  The detail does not show what the backer material might be or how it would be held in place.  Often, vertical studs are doubled around openings and close-packed at corners multiplying the labor and practical problems of placing the backer and the foam.

3.     Placing the spray foam: Is it placed from below via long nozzle inserted up behind the beam?  Installers have told us this is not practical.  Placed from above before the parapet is sheathed?  This can create construction sequence issues.

4.     But the most unpredictable risk is the possibility of condensation forming in the un-vented, un-tempered, space above the foam.

The discussion assumes the necessity of a parapet.  If optimum thermal performance is a goal, then early design discussions should question this necessity.

------------------------------
Alan Swift AIA
Director, Design Integration
dbHMS Design Build Engineering
Chicago IL

Original Message:
Sent: 05-12-2019 17:26
From: Joseph Deringer
Subject: "Details Forum"

The "Details Forum" is a major project in 2019 of the Building Performance Knowledge Community (BP-KC).

The objective is to provide online information that shares good details among architects via a web location within the BP-KC site.  Another focus is to provide a vehicle for publicizing the activities of technically-oriented architects.

A draft detail of a Parapet has been prepared as a test case for implementing a first draft of the "Details Forum."
See the attachment.

Stay tuned for this first draft to be published soon.

Project participants are:

Brad Gellert (lead)

Stephen Katz

Drake Wauters

------------------------------
Joseph Deringer AIA
Institute for Sustainable Performance of Buildings
Berkeley CA
------------------------------

@Margaretha E. Eckhardt AIA Member Emeritus ​, Great point - I was wondering the same thing.  A detail like this should clearly indicate the various barriers and their continuity.  Unfortunately, the detail in the attachment doesn't provide enough information.

------------------------------
Richard J. Linsky, AIA, CSI, CDT, NCARB
Project Architect
Jacobs/Wyper Architects, LLP
Philadelphia, PA
------------------------------

Original Message:
Sent: 06-05-2019 13:36
From: Margaretha Eckhardt
Subject: "Details Forum"

The idea of sharing and discussing details is great!

I do have another comment on the parapet details: I do not find a clear indication of the continuity of the air barrier on these details.  Certainly, making sure we have continuous thermal insulation is important, but if there is air leakage at the roof/wall intersection, then the thermal barrier is compromised and moist air will condense where we don't want it.

• For the wall, spay foam insulation can serve as an air barrier, but how does it transition to membranes?  What happens when we use rigid foam insulation boards instead of the spray foam?
• For the roof, do we want the single-ply membrane to serve as the air barrier, or are we using a air/vapor retarder membrane below the roof insulation to serve this purpose?  In either case, how are penetrations sealed?
• And then, how does the roof air barrier meet the wall air barrier?

------------------------------
Margaretha Eckhardt AIA, CSI, CCS, LEED AP
Payette Associates, Inc.
Boston MA

Original Message:
Sent: 06-04-2019 21:53
From: Richard Linsky
Subject: "Details Forum"

Hi Alan,
Thanks for the great comments you seem to be the only person in this discussion who noticed the condensation issue, so I'll direct my response to you (though it would be nice if others addressed the topic of the OP).  The detail attachment file stated that "The question with the non-Dow details, is there a danger of condensation occurring in the cavity in the parapet wall above the insulation level?"  It looks to me like the non-Dow detail has an unlabeled layer of 5/8" thick sheathing material continuous on back side of the parapet.  That looks like a potential path for vapor transmission into the cavity.  Do you think it would help to break the continuity of the layer like they do in the Dow detail?

------------------------------
Richard Linsky AIA
Project Architect
Jacobs/Wyper Architects, LLP
Springfield PA

Original Message:
Sent: 05-24-2019 12:10
From: Alan Swift
Subject: "Details Forum"

I think a Section here on building details is a great idea and the parapet, a very common problem area, is a perfect place to start.  The details presented compare two routes for the thermal barrier to follow at the parapet.  The discussion suggests that short-cutting the thermal barrier across the base of the parapet will have the advantage of reducing the total surface area of heat-transmitting wall exposed to the exterior. The proposed thermal shortcut uses spray foam inserted between the metal studs.  Some things to consider:

1.     The vertical studs penetrate the spray foam so the R-value of the foam has to be de-rated accordingly.

2.     To place the spray foam as shown would require a horizontal sheet "backer" closing off the space between studs.  The detail does not show what the backer material might be or how it would be held in place.  Often, vertical studs are doubled around openings and close-packed at corners multiplying the labor and practical problems of placing the backer and the foam.

3.     Placing the spray foam: Is it placed from below via long nozzle inserted up behind the beam?  Installers have told us this is not practical.  Placed from above before the parapet is sheathed?  This can create construction sequence issues.

4.     But the most unpredictable risk is the possibility of condensation forming in the un-vented, un-tempered, space above the foam.

The discussion assumes the necessity of a parapet.  If optimum thermal performance is a goal, then early design discussions should question this necessity.

------------------------------
Alan Swift AIA
Director, Design Integration
dbHMS Design Build Engineering
Chicago IL

Original Message:
Sent: 05-12-2019 17:26
From: Joseph Deringer
Subject: "Details Forum"

The "Details Forum" is a major project in 2019 of the Building Performance Knowledge Community (BP-KC).

The objective is to provide online information that shares good details among architects via a web location within the BP-KC site.  Another focus is to provide a vehicle for publicizing the activities of technically-oriented architects.

A draft detail of a Parapet has been prepared as a test case for implementing a first draft of the "Details Forum."
See the attachment.

Stay tuned for this first draft to be published soon.

Project participants are:

Brad Gellert (lead)

Stephen Katz

Drake Wauters

------------------------------
Joseph Deringer AIA
Institute for Sustainable Performance of Buildings
Berkeley CA
------------------------------

Here is an international take on a parapet detail. This project is in China. We were able to work closely with the LDI to improve their standard parapet details. Continuity of both insulation and the weather barrier from the roofing system to the window system over the parapet was the big challenge.

------------------------------
Stephen Katz, AIA, LEED AP BD+C
Gensler
------------------------------

Original Message:
Sent: 06-05-2019 13:36
From: Margaretha Eckhardt
Subject: "Details Forum"

The idea of sharing and discussing details is great!

I do have another comment on the parapet details: I do not find a clear indication of the continuity of the air barrier on these details.  Certainly, making sure we have continuous thermal insulation is important, but if there is air leakage at the roof/wall intersection, then the thermal barrier is compromised and moist air will condense where we don't want it.

• For the wall, spay foam insulation can serve as an air barrier, but how does it transition to membranes?  What happens when we use rigid foam insulation boards instead of the spray foam?
• For the roof, do we want the single-ply membrane to serve as the air barrier, or are we using a air/vapor retarder membrane below the roof insulation to serve this purpose?  In either case, how are penetrations sealed?
• And then, how does the roof air barrier meet the wall air barrier?

------------------------------
Margaretha Eckhardt AIA, CSI, CCS, LEED AP
Payette Associates, Inc.
Boston MA

Original Message:
Sent: 06-04-2019 21:53
From: Richard Linsky
Subject: "Details Forum"

Hi Alan,
Thanks for the great comments you seem to be the only person in this discussion who noticed the condensation issue, so I'll direct my response to you (though it would be nice if others addressed the topic of the OP).  The detail attachment file stated that "The question with the non-Dow details, is there a danger of condensation occurring in the cavity in the parapet wall above the insulation level?"  It looks to me like the non-Dow detail has an unlabeled layer of 5/8" thick sheathing material continuous on back side of the parapet.  That looks like a potential path for vapor transmission into the cavity.  Do you think it would help to break the continuity of the layer like they do in the Dow detail?

------------------------------
Richard Linsky AIA
Project Architect
Jacobs/Wyper Architects, LLP
Springfield PA

Original Message:
Sent: 05-24-2019 12:10
From: Alan Swift
Subject: "Details Forum"

I think a Section here on building details is a great idea and the parapet, a very common problem area, is a perfect place to start.  The details presented compare two routes for the thermal barrier to follow at the parapet.  The discussion suggests that short-cutting the thermal barrier across the base of the parapet will have the advantage of reducing the total surface area of heat-transmitting wall exposed to the exterior. The proposed thermal shortcut uses spray foam inserted between the metal studs.  Some things to consider:

1.     The vertical studs penetrate the spray foam so the R-value of the foam has to be de-rated accordingly.

2.     To place the spray foam as shown would require a horizontal sheet "backer" closing off the space between studs.  The detail does not show what the backer material might be or how it would be held in place.  Often, vertical studs are doubled around openings and close-packed at corners multiplying the labor and practical problems of placing the backer and the foam.

3.     Placing the spray foam: Is it placed from below via long nozzle inserted up behind the beam?  Installers have told us this is not practical.  Placed from above before the parapet is sheathed?  This can create construction sequence issues.

4.     But the most unpredictable risk is the possibility of condensation forming in the un-vented, un-tempered, space above the foam.

The discussion assumes the necessity of a parapet.  If optimum thermal performance is a goal, then early design discussions should question this necessity.

------------------------------
Alan Swift AIA
Director, Design Integration
dbHMS Design Build Engineering
Chicago IL

Original Message:
Sent: 05-12-2019 17:26
From: Joseph Deringer
Subject: "Details Forum"

The "Details Forum" is a major project in 2019 of the Building Performance Knowledge Community (BP-KC).

The objective is to provide online information that shares good details among architects via a web location within the BP-KC site.  Another focus is to provide a vehicle for publicizing the activities of technically-oriented architects.

A draft detail of a Parapet has been prepared as a test case for implementing a first draft of the "Details Forum."
See the attachment.

Stay tuned for this first draft to be published soon.

Project participants are:

Brad Gellert (lead)

Stephen Katz

Drake Wauters

------------------------------
Joseph Deringer AIA
Institute for Sustainable Performance of Buildings
Berkeley CA
------------------------------

Thank you for sharing the parapet detail, Stephen, for the project in China.  Can you tell me how the constructor installed the rock wool insulation?  It appears that it would would need to be installed prior to installing the cement board sheathing which would expose the insulation to the elements until such time as the sheathing would be installed. I ask because we are regularly challenged by the installers of parapet insulation claiming they cannot install the insulation as detailed due to a lack of access. Thank you again!

------------------------------
Chris Kirschner AIA
partner
BDG Architects
Tampa FL
------------------------------

Original Message:
Sent: 06-30-2019 19:03
From: Stephen Katz
Subject: "Details Forum"

Here is an international take on a parapet detail. This project is in China. We were able to work closely with the LDI to improve their standard parapet details. Continuity of both insulation and the weather barrier from the roofing system to the window system over the parapet was the big challenge.

------------------------------
Stephen Katz, AIA, LEED AP BD+C
Gensler

Original Message:
Sent: 06-05-2019 13:36
From: Margaretha Eckhardt
Subject: "Details Forum"

The idea of sharing and discussing details is great!

I do have another comment on the parapet details: I do not find a clear indication of the continuity of the air barrier on these details.  Certainly, making sure we have continuous thermal insulation is important, but if there is air leakage at the roof/wall intersection, then the thermal barrier is compromised and moist air will condense where we don't want it.

• For the wall, spay foam insulation can serve as an air barrier, but how does it transition to membranes?  What happens when we use rigid foam insulation boards instead of the spray foam?
• For the roof, do we want the single-ply membrane to serve as the air barrier, or are we using a air/vapor retarder membrane below the roof insulation to serve this purpose?  In either case, how are penetrations sealed?
• And then, how does the roof air barrier meet the wall air barrier?

------------------------------
Margaretha Eckhardt AIA, CSI, CCS, LEED AP
Payette Associates, Inc.
Boston MA

Original Message:
Sent: 06-04-2019 21:53
From: Richard Linsky
Subject: "Details Forum"

Hi Alan,
Thanks for the great comments you seem to be the only person in this discussion who noticed the condensation issue, so I'll direct my response to you (though it would be nice if others addressed the topic of the OP).  The detail attachment file stated that "The question with the non-Dow details, is there a danger of condensation occurring in the cavity in the parapet wall above the insulation level?"  It looks to me like the non-Dow detail has an unlabeled layer of 5/8" thick sheathing material continuous on back side of the parapet.  That looks like a potential path for vapor transmission into the cavity.  Do you think it would help to break the continuity of the layer like they do in the Dow detail?

------------------------------
Richard Linsky AIA
Project Architect
Jacobs/Wyper Architects, LLP
Springfield PA

Original Message:
Sent: 05-24-2019 12:10
From: Alan Swift
Subject: "Details Forum"

I think a Section here on building details is a great idea and the parapet, a very common problem area, is a perfect place to start.  The details presented compare two routes for the thermal barrier to follow at the parapet.  The discussion suggests that short-cutting the thermal barrier across the base of the parapet will have the advantage of reducing the total surface area of heat-transmitting wall exposed to the exterior. The proposed thermal shortcut uses spray foam inserted between the metal studs.  Some things to consider:

1.     The vertical studs penetrate the spray foam so the R-value of the foam has to be de-rated accordingly.

2.     To place the spray foam as shown would require a horizontal sheet "backer" closing off the space between studs.  The detail does not show what the backer material might be or how it would be held in place.  Often, vertical studs are doubled around openings and close-packed at corners multiplying the labor and practical problems of placing the backer and the foam.

3.     Placing the spray foam: Is it placed from below via long nozzle inserted up behind the beam?  Installers have told us this is not practical.  Placed from above before the parapet is sheathed?  This can create construction sequence issues.

4.     But the most unpredictable risk is the possibility of condensation forming in the un-vented, un-tempered, space above the foam.

The discussion assumes the necessity of a parapet.  If optimum thermal performance is a goal, then early design discussions should question this necessity.

------------------------------
Alan Swift AIA
Director, Design Integration
dbHMS Design Build Engineering
Chicago IL

Original Message:
Sent: 05-12-2019 17:26
From: Joseph Deringer
Subject: "Details Forum"

The "Details Forum" is a major project in 2019 of the Building Performance Knowledge Community (BP-KC).

The objective is to provide online information that shares good details among architects via a web location within the BP-KC site.  Another focus is to provide a vehicle for publicizing the activities of technically-oriented architects.

A draft detail of a Parapet has been prepared as a test case for implementing a first draft of the "Details Forum."
See the attachment.

Stay tuned for this first draft to be published soon.

Project participants are:

Brad Gellert (lead)

Stephen Katz

Drake Wauters

------------------------------
Joseph Deringer AIA
Institute for Sustainable Performance of Buildings
Berkeley CA
------------------------------

Original Message------

Thank you for sharing the parapet detail, Stephen, for the project in China.  Can you tell me how the constructor installed the rock wool insulation?  It appears that it would would need to be installed prior to installing the cement board sheathing which would expose the insulation to the elements until such time as the sheathing would be installed. I ask because we are regularly challenged by the installers of parapet insulation claiming they cannot install the insulation as detailed due to a lack of access. Thank you again!

------------------------------
Chris Kirschner AIA
partner
BDG Architects
Tampa FL
------------------------------

Chris, great question. It was a little while ago but from what I recall the contractor staged the parapet work such that the sheathing and weather barrier were installed almost immediately after the insulation to avoid what you describe. This all fell under means and methods of the contractor but they seemed to be fine with the approach. I will tell you that the detailing of the parapet for this project took a considerable amount of energy on everyone's part. Thanks, Stephen.

------------------------------
Stephen Katz AIA
Gensler - Chicago
Chicago IL
------------------------------

Original Message:
Sent: 07-02-2019 09:13
From: Chris Kirschner
Subject: "Details Forum"

Thank you for sharing the parapet detail, Stephen, for the project in China.  Can you tell me how the constructor installed the rock wool insulation?  It appears that it would would need to be installed prior to installing the cement board sheathing which would expose the insulation to the elements until such time as the sheathing would be installed. I ask because we are regularly challenged by the installers of parapet insulation claiming they cannot install the insulation as detailed due to a lack of access. Thank you again!

------------------------------
Chris Kirschner AIA
partner
BDG Architects
Tampa FL

Original Message:
Sent: 06-30-2019 19:03
From: Stephen Katz
Subject: "Details Forum"

Here is an international take on a parapet detail. This project is in China. We were able to work closely with the LDI to improve their standard parapet details. Continuity of both insulation and the weather barrier from the roofing system to the window system over the parapet was the big challenge.

------------------------------
Stephen Katz, AIA, LEED AP BD+C
Gensler

Original Message:
Sent: 06-05-2019 13:36
From: Margaretha Eckhardt
Subject: "Details Forum"

The idea of sharing and discussing details is great!

I do have another comment on the parapet details: I do not find a clear indication of the continuity of the air barrier on these details.  Certainly, making sure we have continuous thermal insulation is important, but if there is air leakage at the roof/wall intersection, then the thermal barrier is compromised and moist air will condense where we don't want it.

• For the wall, spay foam insulation can serve as an air barrier, but how does it transition to membranes?  What happens when we use rigid foam insulation boards instead of the spray foam?
• For the roof, do we want the single-ply membrane to serve as the air barrier, or are we using a air/vapor retarder membrane below the roof insulation to serve this purpose?  In either case, how are penetrations sealed?
• And then, how does the roof air barrier meet the wall air barrier?

------------------------------
Margaretha Eckhardt AIA, CSI, CCS, LEED AP
Payette Associates, Inc.
Boston MA

Original Message:
Sent: 06-04-2019 21:53
From: Richard Linsky
Subject: "Details Forum"

Hi Alan,
Thanks for the great comments you seem to be the only person in this discussion who noticed the condensation issue, so I'll direct my response to you (though it would be nice if others addressed the topic of the OP).  The detail attachment file stated that "The question with the non-Dow details, is there a danger of condensation occurring in the cavity in the parapet wall above the insulation level?"  It looks to me like the non-Dow detail has an unlabeled layer of 5/8" thick sheathing material continuous on back side of the parapet.  That looks like a potential path for vapor transmission into the cavity.  Do you think it would help to break the continuity of the layer like they do in the Dow detail?

------------------------------
Richard Linsky AIA
Project Architect
Jacobs/Wyper Architects, LLP
Springfield PA

Original Message:
Sent: 05-24-2019 12:10
From: Alan Swift
Subject: "Details Forum"

I think a Section here on building details is a great idea and the parapet, a very common problem area, is a perfect place to start.  The details presented compare two routes for the thermal barrier to follow at the parapet.  The discussion suggests that short-cutting the thermal barrier across the base of the parapet will have the advantage of reducing the total surface area of heat-transmitting wall exposed to the exterior. The proposed thermal shortcut uses spray foam inserted between the metal studs.  Some things to consider:

1.     The vertical studs penetrate the spray foam so the R-value of the foam has to be de-rated accordingly.

2.     To place the spray foam as shown would require a horizontal sheet "backer" closing off the space between studs.  The detail does not show what the backer material might be or how it would be held in place.  Often, vertical studs are doubled around openings and close-packed at corners multiplying the labor and practical problems of placing the backer and the foam.

3.     Placing the spray foam: Is it placed from below via long nozzle inserted up behind the beam?  Installers have told us this is not practical.  Placed from above before the parapet is sheathed?  This can create construction sequence issues.

4.     But the most unpredictable risk is the possibility of condensation forming in the un-vented, un-tempered, space above the foam.

The discussion assumes the necessity of a parapet.  If optimum thermal performance is a goal, then early design discussions should question this necessity.

------------------------------
Alan Swift AIA
Director, Design Integration
dbHMS Design Build Engineering
Chicago IL

Original Message:
Sent: 05-12-2019 17:26
From: Joseph Deringer
Subject: "Details Forum"

The "Details Forum" is a major project in 2019 of the Building Performance Knowledge Community (BP-KC).

The objective is to provide online information that shares good details among architects via a web location within the BP-KC site.  Another focus is to provide a vehicle for publicizing the activities of technically-oriented architects.

A draft detail of a Parapet has been prepared as a test case for implementing a first draft of the "Details Forum."
See the attachment.

Stay tuned for this first draft to be published soon.

Project participants are:

Brad Gellert (lead)

Stephen Katz

Drake Wauters

------------------------------
Joseph Deringer AIA
Institute for Sustainable Performance of Buildings
Berkeley CA
------------------------------

@Joseph J. Deringer AIA Member Emeritus, I'm enjoying this discussion, but I'm wondering about the goal of posting the detail in this forum.  Is the intent to come up with constructive criticism that will improve the detail that is ultimately posted on the "Details Forum"?  Or is it simply a point of departure for discussing the depicted condition?  TIA for clarifying! ​​​

------------------------------
Richard J. Linsky, AIA, CSI, CDT, NCARB
Project Architect
Jacobs/Wyper Architects, LLP
Philadelphia, PA
------------------------------

Original Message:
Sent: 05-12-2019 17:26
From: Joseph Deringer
Subject: "Details Forum"

The "Details Forum" is a major project in 2019 of the Building Performance Knowledge Community (BP-KC).

The objective is to provide online information that shares good details among architects via a web location within the BP-KC site.  Another focus is to provide a vehicle for publicizing the activities of technically-oriented architects.

A draft detail of a Parapet has been prepared as a test case for implementing a first draft of the "Details Forum."
See the attachment.

Stay tuned for this first draft to be published soon.

Project participants are:

Brad Gellert (lead)

Stephen Katz

Drake Wauters

------------------------------
Joseph Deringer AIA
Institute for Sustainable Performance of Buildings
Berkeley CA
------------------------------

Perhaps the parapet detail can serve as an example that we can all comment on and once it has been updated to address the group's comments it can serve as a model for development of other details.  It is not realistic for us to develop a complete set of all possible details, but if there is a set of good, thoroughly thought-through generic details, it would be a good resource for working through the specific details for our projects.

------------------------------
Margaretha Eckhardt AIA, CSI, CCS, LEED AP
Payette Associates, Inc.
Boston MA
------------------------------

Original Message:
Sent: 06-05-2019 19:29
From: Richard Linsky
Subject: "Details Forum"

@Joseph J. Deringer AIA Member Emeritus, I'm enjoying this discussion, but I'm wondering about the goal of posting the detail in this forum.  Is the intent to come up with constructive criticism that will improve the detail that is ultimately posted on the "Details Forum"?  Or is it simply a point of departure for discussing the depicted condition?  TIA for clarifying! ​​​

------------------------------
Richard J. Linsky, AIA, CSI, CDT, NCARB
Project Architect
Jacobs/Wyper Architects, LLP
Philadelphia, PA

Original Message:
Sent: 05-12-2019 17:26
From: Joseph Deringer
Subject: "Details Forum"

The "Details Forum" is a major project in 2019 of the Building Performance Knowledge Community (BP-KC).

The objective is to provide online information that shares good details among architects via a web location within the BP-KC site.  Another focus is to provide a vehicle for publicizing the activities of technically-oriented architects.

A draft detail of a Parapet has been prepared as a test case for implementing a first draft of the "Details Forum."
See the attachment.

Stay tuned for this first draft to be published soon.

Project participants are:

Brad Gellert (lead)

Stephen Katz

Drake Wauters

------------------------------
Joseph Deringer AIA
Institute for Sustainable Performance of Buildings
Berkeley CA
------------------------------

Yes, the intent of the forum is to post details that we can all comment and refine based on the comments received. The original parapet detail posted, was not intended as the final or best example of how to solve that condition, but an approach to be discussed.

------------------------------
[E. Bradford] [Glellert] [AIA]
[TDA]
[Willoughby] [Ohio]
------------------------------

Original Message:
Sent: 06-06-2019 11:48
From: Margaretha Eckhardt
Subject: "Details Forum"

Perhaps the parapet detail can serve as an example that we can all comment on and once it has been updated to address the group's comments it can serve as a model for development of other details.  It is not realistic for us to develop a complete set of all possible details, but if there is a set of good, thoroughly thought-through generic details, it would be a good resource for working through the specific details for our projects.

------------------------------
Margaretha Eckhardt AIA, CSI, CCS, LEED AP
Payette Associates, Inc.
Boston MA

Original Message:
Sent: 06-05-2019 19:29
From: Richard Linsky
Subject: "Details Forum"

@Joseph J. Deringer AIA Member Emeritus, I'm enjoying this discussion, but I'm wondering about the goal of posting the detail in this forum.  Is the intent to come up with constructive criticism that will improve the detail that is ultimately posted on the "Details Forum"?  Or is it simply a point of departure for discussing the depicted condition?  TIA for clarifying! ​​​

------------------------------
Richard J. Linsky, AIA, CSI, CDT, NCARB
Project Architect
Jacobs/Wyper Architects, LLP
Philadelphia, PA

Original Message:
Sent: 05-12-2019 17:26
From: Joseph Deringer
Subject: "Details Forum"

The "Details Forum" is a major project in 2019 of the Building Performance Knowledge Community (BP-KC).

The objective is to provide online information that shares good details among architects via a web location within the BP-KC site.  Another focus is to provide a vehicle for publicizing the activities of technically-oriented architects.

A draft detail of a Parapet has been prepared as a test case for implementing a first draft of the "Details Forum."
See the attachment.

Stay tuned for this first draft to be published soon.

Project participants are:

Brad Gellert (lead)

Stephen Katz

Drake Wauters

------------------------------
Joseph Deringer AIA
Institute for Sustainable Performance of Buildings
Berkeley CA
------------------------------

Looking forward to the first draft. Thanks for sharing!

------------------------------
Sarah Gudeman
Mechanical Engineer
Morrissey Engineering
Omaha NE
------------------------------

Original Message:
Sent: 05-12-2019 17:26
From: Joseph Deringer
Subject: "Details Forum"

The "Details Forum" is a major project in 2019 of the Building Performance Knowledge Community (BP-KC).

The objective is to provide online information that shares good details among architects via a web location within the BP-KC site.  Another focus is to provide a vehicle for publicizing the activities of technically-oriented architects.

A draft detail of a Parapet has been prepared as a test case for implementing a first draft of the "Details Forum."
See the attachment.

Stay tuned for this first draft to be published soon.

Project participants are:

Brad Gellert (lead)

Stephen Katz

Drake Wauters

------------------------------
Joseph Deringer AIA
Institute for Sustainable Performance of Buildings
Berkeley CA
------------------------------