Choosing construction adhesives can be one of the more overwhelming parts of material selection for a build.
However, just like with caulking sealants, the same types of low-VOC polymers are also used in construction adhesives, window and door installs, flooring, and roofs.
And there are some really good options out there.
The article covers the best types and the best brands for those who are chemically sensitive or who want a very low-VOC non-toxic option.
This article contains affiliate links, upon purchase I make a small commission at no extra cost to you.
1. Construction Adhesives
Construction adhesives are used for subfloors, to install doors (glue down threshold), to build stairs, exterior brickwork, install some shower walls, under countertops, and more.
i. AFM Almighty Adhesive
AFM Almighty Adhesive is the best adhesive I have ever tested. I had absolutely no problem and no reaction to smelling it while it was wet.
This was a pleasant surprise after all the other glues and silicones I had been testing.
It is a highly tolerable very low odor, multipurpose adhesive (make sure it’s right for your application). The PSI is 500 (in other words it’s a very strong adhesive).
It is a polyether (30-80%) and nepheline syenite (30-60%) adhesive, with 1-5% amino silane.
I used Almighty to install my shower, on subfloors, and my countertops (it can even be used on waterfall countertops). I would use this anywhere and everywhere this can be used since it’s the healthiest adhesive I have found.
Insider tip, this is the same formula as Build Secure by Chemlink.
Where to buy: Buy Almighty from Green Design Center.
ii. Chemlink WallSecure
Chemlink WallSecure is made for bonding drywall, gypsum, landscape blocks, capstones, stone, foam, fiberglass, FRP panels, and ceiling systems.
I haven’t tested this one but this brand makes great low-toxin adhesives.
Where to buy: Buy from Amazon.
iii. Chemlink M-1
Chemlink M-1 can perform as both an adhesive and a sealant.
It adheres to a wide range of construction materials including PVC, EPDM, most metals, wood, glass, masonry concrete, fiberglass, and solvent-sensitive foams so it works in almost any situation requiring a sealant.
With a 400 psi and 525% elongation, it also performs as a structural adhesive.
M-1 is a solvent-free silane-modified polyether.
Where to buy: Buy from Amazon.
IV. Ecotite ET 5500 and 9500
This is another good brand that is well-liked by the chemically sensitive.
Their ET 5500 is an adhesive that works on multiple surfaces: PVC, concrete, glass, aluminum, painted surfaces, wood plywood, marble, metal, and more.
At about one week most would find this odorless. At two weeks it seemed totally offgassed. I was very happy with this one.
The 9500 is used for windows, doors, trim, and some kitchen applications. At three weeks it’s still not odorless/offgassed. I’m not as happy with this one as it did not stop offgassing by three weeks.
The bottles say odorless, but the point in time that it is odorless depends on the conditions (curing rate) and how sensitive your sense of smell is.
Right off the bat, the 5500 is significantly milder, and lower odor than conventional adhesives.
Where to buy: The links to the 5500 and 9500 are to a Canadian store, but you can find this product in the US as well.
Non-Toxic Adhesives for Hardwood Floor Installation
The type of glue you will need for a flooring installation depends on the method: with a Floating Floor, the planks are clicked together and installed over an underlayment but not glued or nailed down. Tongue and groove glue is often used on the edges (Roberts is zero-VOC). With Nail Down installation an underlayment is used and the floor is not glued down.
i. Glue Assist
This installation involves gluing down and nailing the floor. This is often used for wide planks and/or when there are big fluctuations in humidity. If you want to avoid glue, don’t go for wide planks. Glues can be silane-modified polyether or polyurethane. Silane-modified types are lower toxicity, but be sure to check the warranty for the floor to make sure that is approved.
ii. Glue Down
In this method, the glue is installed evenly on the floor. Many of the glues are polyurethane. Some are 0-VOC like Bostik Greenforce (which does say it’s a urethane adhesive). This method is often used over concrete.
Non-Toxic Adhesives for Window & Door Install
To install windows into the opening you can use AFM Caulking Compound or DuraLink. Make sure to check the warranty to make sure this is approved. After the window is installed, seal around it with your choice of silicone after install.
More options are above in the article.
Under doors you can use DuraLink.
Non-Toxic Adhesives for Roofing
Around penetrations, flashing, gutters for metal and asphalt: use Durasil Silicone or Chemlink DuraLink.
Around a chimney, use metal flashing with sealant on the edges. Around a boot, use silicone like Durasil.
Sika Flex 715 is silane-terminated polyether. It’s the lowest VOC sealant I have seen at 5.5 g/l VOC. It’s extremely low in odor but not all that different from AFM Almighty in odor. It is primarily used as a roof sealant. The PSI is not very high at 85 PSI. It is used on EPDM and metal roofs (often RV roofs). It adheres well to ceramics and plastics as well.
Corinne Segura holds certificates in Building Biology, Healthier Materials and Sustainable Buildings, and more. She has 10 years of experience helping others create healthy homes.
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AS
Hi Corrine,
Would the AFM Mighty adhesive work for glueing the first plank of solid hardwood and then using the nail down method for the rest. Our contractor said he prefers to glue down the first plank and uses Bona sausage glue, although they are green guard gold and zero voc, the ingredients list plasticizers and I’m worried about those.
Thank you in advance.
Corinne Segura, Building Biologist
yes it would likely work, ask your contrator. They both likely have the same plasticizers though. That doesnt matter under a wood floor as it will be blocked.
Amy de Wall
Hi Corrine,
Firstly, thank you SO much for kindly sharing all your knowledge. I’ve been going through all your articles for our new build coming up. I’m feeling overhwhelmed as I’m in Australia and so most products mentioned aren’t available here.
We are not chemically sensitive, however we are health fanatics. We are building a certified PassivHaus because of this. My question is, is VOC offgassing less of an overall concern in a passivehaus than non passive haus, given the HRV filter system?
Thank you SO much,
Amy
Corinne Segura, Building Biologist
air exchange definitely helps especially in a very tight build. i would still go low VOC and avoid all the products in the article on most toxic materials to avoid in a build
Gina
The previous comment about the silane based adhesive still off-gassing after weeks is very concerning. I’m about to have engineered wood floors extended and it’s going to require glue. We were going to use Bona because I thought silane would be the better option. Is it better to go with a low odor/low voc urethane adhesive?
Corinne Segura, Building Biologist
I don’t know, I’ve always advised chemically sensitive clients to not do a glue down installation so I don’t have a lot of feedback on that. Urethanes have always traditionally offgassed slower but I don’t know if in this case they can offgas better through layers of flooring.
Michael
All of the Zero VOC wood flooring adhesives I’ve tested (Bona, Bostik, Fortane) give off significant (7,000-38,000 ppb) VOCs when you open the pail and apply them to the floor.
I have been told that their VOC emissions should approach zero after they are fully cured. However, on two separate occasions in Florida, I have seen significant VOC emissions from these products extend beyond 3-4 weeks. It seems completely irresponsible to label these as “Zero VOC”. It should be illegal.
You can find a little more about some of the issues that I’m facing in this question:
https://www.greenbuildingadvisor.com/question/silane-based-zero-voc-wood-flooring-adhesives-and-off-gassing
Corinne Segura, Building Biologist
there is a lot going on in that link, first cali cork flooring is almost certainly not 0 VOC even if the company says it’s really low. Maybe they tested a sample and not the new flooring shipment. Most flooring has offgassing even if it’s natural VOCs, and those are often not counted by the companies and the biggest likely offgasser.
Also those monitors are not very accurate so that’s another big problem in that testing.
If it’s a sil terminated polyether that is usually fairly fast to offgas in a week or so. If it’s a polyurethane that could be slower even if the initial VOCs are lower when wet.
I don’t know what’s going on with these specific products, it’s possible that they are not VOC until two weeks as they could still list the product as 0 VOC. There have been various FTC violations about VOC claims so it’s possible something is up. What are you using to test those products at 3-4 weeks and is there nothing else new like new flooring?
if you are chemically sensitive you should definitely trust your own senses if you can still notice it at 3-4 weeks, I always try to avoid glue down plank flooring for those who are extremely sensitive.
Corinne Segura, Building Biologist
I also see the response in GBA that if it’s really thick it sometimes doesnt cure through the floor. That is very interesting and good to know.
Jeremy Bazata
Hi Corrine,
Replacing tub. Floor is our about 1/2 inch and needs to be leveled – what material is safe to use for floor leveling? Then need to seat the tub – I couldn’t find in anything on this in your bathtub and shower article. Any help you could provide would be fantastic!
Thank you so much,
Jeremy
Corinne Segura
There’s an article on self leveling cement, and one for caulking, for around the toilet. As for the toilet wax ring I think any of them should be fine.