Regarding Luaun Underlayment
Our rolls of Marmoleum are here at last. But in the booklet I see that the manufacturer advises against an underlayment of Luaun plywood, which is exactly what I used. It says that the chemicals used in the manufacture of Luaun “has caused permanent staining” in some cases. Our 1/4″ underlayment was put down almost…
Our rolls of Marmoleum are here at last. But in the booklet I see that the manufacturer advises against an underlayment of Luaun plywood, which is exactly what I used. It says that the chemicals used in the manufacture of Luaun “has caused permanent staining” in some cases.
Our 1/4″ underlayment was put down almost five years ago and left exposed all that time, so I’m wondering if these chemicals have off-gassed or dissipated in some way. Anyway, I’m writing to ask if anybody has had some experience in this regard.
FIrstly, the statement regarding chemicals is both right and wrong. The chemical in Lauan plywood that often causes concern is Formaldehyde which is part of the glue. The off gassing of the formaldehyde should be complete over the 5 years you say it has been down. Is there any noticable “peppery” smell? I liken back to the smell of paneling that we installed in garages and basements as a kid. It had that peppery paneling smell and in fact that was the Formaldehyde that we were smelling as kids and believe it or not I am still alive and healthy where people would like to scare you into believing it causes cancer.
Next the concern shifts to the type of adhesive. If there is a black glue line that can be seen on the edge of the plywood…assuming you can even see the edge of the plywood…then the panel was made with a Phenolic glue line and that is both good and bad. If it is Phenolic it will contain much less Formadehyde, but it can have what we call glue “Bleed through”. This means that over time and with heat, the Phenolic resin can move through the thin layer of veneer on the face of the panel and made a dark spot on the face of the panel that transfers to the vinyl. This is what has caused discoloration in the past to my knowledge.
I also have an unproven theory that the pitch that is inherenty in the Lauan can also cause a larger brown stain.
We introduced a product by the name of SurePly into the market back in 1992 and eliminated any pitch pockets from the material and have never had a discoloration problem ever.
My best recommendation to you is to put down a new layer of a warranted underlayment on top of what is already down. SurePly is available at Lowe’s. Closely follow the installation instructions that you can find on the web at http://www.sureply.com.
Now so that this is not seen as a commercial for SurePly or if it’s not available in your area, then look into other warranted underlayments. There are many on the market and the warranty is very important. While it costs a little more to put down another layer, it is cheap insurance against ruining the cost of the entire floor.
I hope this helps, please let me know how you project turns out.
Regards,
Sam