Sashco big stretch caulk ok for air sealing?
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I am building a new house in zone 5. I started using Sashco’s big stretch caulk for interior air sealing, wood to wood butt joints, top plate and bottom plate. It says it’s a caulk/sealant and just wondered if it’s a suitable interior air sealer or if it’s not recommended? I wanted to make sure I got the air sealing right because drywallers just look at you funny when you ask about them doing the airtight drywall approach. 🙂
Thanks,
Michael
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Replies
I have no experience with this product, but the Safety Data Sheet is concerning. It contains a known carcinogen and can be toxic to organs. I've used NovaLink 35 on a few sealing projects and have no complaints. It is ultra low VOC and contains no known carcinogens.
Michael,
Big Stretch is almost all I use. Its ability to deal with movement without cracking makes it a great choice. The only two downsides I can think of are the price, and that it takes a lot longer than most caulking to cure. That means keeping other trades and their associated messes away for a while.
I think you have to be careful evaluating products on the basis of their Safety data sheets. The presence of toxic ingredients doesn't tell you whether they are persistent, or only occur during installation. Unless a sealant has worrying ingredients that off-gass over time, I can see how their presence makes any difference.
I've used a lot of Big Stretch in the past and have found it a high quality product. Like Steve, though, I am concerned by the safety data sheet. It's listed as a Class 1B carcinogen, meaning it is known or presumed to cause cancer in humans, through animal testing. That's a higher risk than Class 2, "suspected human carcinogen." It's composed of water, limestone, petroleum distillates, ethylene glycol (antifreeze), another ethylene compound, and ammonium hydroxide (ammonia). After reading the sheet I would not rule out using it, but I would be careful to ensure adequate ventilation until it's cured, or I'd wear a respirator if using a lot of it.
Another product I've used a fair bit and that performs quite similarly but is an ultra-low VOC product is Pro Clima Contega HF: https://foursevenfive.com/product/contega-hf/. It's not inexpensive but it is safe, flexible and adheres well.
Personally, I don't like using goop any more than necessary, and would recommend using gaskets where possible: http://conservationtechnology.com/building_weatherseals.html.
Thank you for your responses, it is appreciated!