Historic Resources Committee

 View Only

Community HTML

Renaissance Schallaburg Figures in a facade

Quick Links

Who we are

The mission of the Historic Resources Committee (HRC) is to identify, understand, and preserve architectural heritage, both nationally and internationally. HRC is engaged in promoting the role of the historic architect within the profession through the development of information and knowledge among members, allied professional organizations, and the public.

  • 1.  Alternative for 1940s gypsum board exterior siding?

    Posted 12-10-2020 03:49 PM
    My team manages a number of buildings in Los Alamos, NM that were built in the 1940s as part of the Manhattan Project. These buildings have been determined eligible for inclusion on the National Register of Historic Places and are part of the Manhattan Project National Historical Park.

    During the war, these buildings were intended to be temporary, and a number of them had what appears to be gypsum board used for exterior siding. The gypsum board exterior siding was later covered with asbestos shingles when the buildings transitioned to longer-term use.  As part of ongoing maintenance, replacement of the asbestos shingles with approved non-asbestos shingles has been proposed. However, we'd really like to remove the shingles altogether and restore the exterior closer to its original appearance. One idea I had is to use a cement board product to achieve a similar, but more durable, result. We will, of course, consult with the State Historic Preservation Office, but I wanted to do some further research first. 

    Any thoughts or recommendations on using cement board as a replacement, or suggestions for an alternative product would be appreciated.

    ------------------------------
    Cameron Townsend Assoc. AIA
    Los Alamos, NM
    ------------------------------
    2024 HRC Taliesin West


  • 2.  RE: Alternative for 1940s gypsum board exterior siding?

    Posted 12-11-2020 06:49 PM
    Hi Cameron

    Consult with the NMSHPO Jeff Pappas sooner, rather than later. They will
    assign a staff person to work with you.

    Victor Johnson, AIA
    Santa Fe


    please do not add our email address to any list-serve or other email list.
    thank you.


    2024 HRC Taliesin West


  • 3.  RE: Alternative for 1940s gypsum board exterior siding?

    Posted 12-11-2020 07:24 PM
    For several reasons you could use Hardboard smooth side painted to match. However it's thickness is not the same. Therefore you might consult with them or competitors about their exterior board assembled with an exterior (waterproof) gypsum wall board like the type surrounding shower stalls. This gives appearance, smooth texture on both sides and fire resistant exterior cladding. You should wrap the gypboard on its outside with Tyvek or equal to prevent air pressure penetration.  Choice of nails or screws is important due to dissimilar substrate and you may want to have contractor predrill before screwing with coated headless screws. Hardie can pre prime or paint finish color to match your specs.

    ------------------------------
    Barry Sulam
    [https://www.cascadianow.org/learning-places][Southwest Regional Historical Architect, Ret.]
    ------------------------------

    2024 HRC Taliesin West


  • 4.  RE: Alternative for 1940s gypsum board exterior siding?

    Posted 12-11-2020 07:52 PM
    Aloha Cameron,

    The choice of durable cement board may be the best choice if the period of significance (POS) is the 1940s, and if the shingles were added after that POS.  Would it be possible for you to share the documentation that was submitted for the determination of eligibility?

    Hope this idea (of tying the decision about material choice to the eligibility reasoning) is helpful.

    ------------------------------
    Ann Yoklavich, Assoc. AIA
    Architectural Historian
    MASON Architecture and Historic Consulting
    Honolulu, HI
    ------------------------------

    2024 HRC Taliesin West


  • 5.  RE: Alternative for 1940s gypsum board exterior siding?

    Posted 12-14-2020 10:01 AM

    Cameron,

     

    I think you've hit on the best idea I had for a durable, but similar looking finish. I've had experience with Hardie board – we used it on my graduate thesis – design and construction of a house in 1999.  We used both plank and sheet products.  Since I still live in the area I drive by periodically and it still looks good. I'm not sure it's even been repainted – it's the same color and I'm pretty certain it's had 2 or 3 owners. The plank was installed over furring strips to create a ventilated rainscreen cladding – kind of a harsh exposure in Kansas, but I don't see any issues and all we did was back prime the planks.

     

    Julia Mathias Manglitz AIA, NCARB, LEED AP
    ASSOCIATE PRINCIPAL

    TREANORHL
    o 785.235.0012
    c
    785.331.9169

    treanorhl.com




    2024 HRC Taliesin West


  • 6.  RE: Alternative for 1940s gypsum board exterior siding?

    Posted 12-15-2020 05:27 PM
    That is what I would recommend.  Only issue will be the joints as it is a board.  Final finishing will make or break it as a effective solution.  As always...

    ------------------------------
    Wm. Parry AIA
    Architect & Architectural Historian
    Idea Studios
    Santa Rosa CA
    ------------------------------

    2024 HRC Taliesin West


  • 7.  RE: Alternative for 1940s gypsum board exterior siding?

    Posted 12-14-2020 11:22 PM
    Cameron

    You have not mentioned the condition of the gyp-board and if it has any surface coatings (paint etc.?).  Why is it necessary to replace this original material?  If it is painted gyp-board it should be easily repaired. I assume there are myriad nail holes and other mis-treatments from the addition of multiple regimens of cement shingles. 

    Having spent several years growing up at the Naval Ordinance Test Station in the Mohave Desert I suspect your weather is dry enough that paint on the surface should be sufficient. If there is moisture damage not generated by intrusion through the nail holes the long term preservation may require some areas to be impregnated. 

    Photos and additional information would facilitate discussion of treatment options. 

    Best Wishes 

    Charles

    Charles A Phillips, AIA, AIC-pa

    433 Phillips Rd
    Nacogdoches, Tx 75964 


    640 Brookstown Ave
    Winston Salem, NC 27101

    conservearchitecture.com
    336-918-3668




    2024 HRC Taliesin West


  • 8.  RE: Alternative for 1940s gypsum board exterior siding?

    Posted 12-22-2020 07:45 PM

    Thank you all for your responses! As someone just starting out their career in historic preservation, I haven't had exposure to many of these materials. I'm glad to have you all as an additional resource. 

    Overall, your comments confirmed that we need more information about the original material and its condition. None of us have actually seen the original siding beyond tiny peeks through damaged shingles. After some more research, we found some historical photos of other buildings (since demolished) that were constructed nearby around the same time. It looks like they had a mastic applied at the joints of the gypsum sheathing. A coworker also found this article about exterior gypsum sheathing that describes it as being more weather resistant than I had originally thought. We're now thinking there may be some sort of weather barrier underneath too. Someone on here also commented that we may be able to patch the nail holes from the shingles. Between these discoveries and your comments, I have more hope for preserving the original siding or covering it with something more in-kind than I originally did! 

    We have briefly talked about the siding with the NMSHPO while we were discussing some restoration work to the roof and interior that will take place this spring/summer. Right now our plan is to wait until that work takes place and use it as an opportunity to get a good look at what is underneath the shingles. It sounds like they may opt to just replace the damaged shingles for this round of work, but we can be doing our research to be ready when it is time to address the exterior siding. Sounds like cement board could be an option to have in our pockets, but it may not be necessary. I'll try to remember to share pictures when we remove the shingles. 

    Thanks!



    ------------------------------
    Cameron Townsend Assoc. AIA
    Los Alamos NM
    ------------------------------

    2024 HRC Taliesin West