I have 3000 sf of new moabi (Brazilian hardwood) wide plank (7 1/2″) unfinished engineered floor installed over gycrete radiant heating floor. The planks are tongue and groove and the floor is some of the most flat the installer and myself have seen. However, upon completion of the glue down we observe the next day: (1) the end of the planks where they butt to a wall and in the middle of the wall area have bowed up, sometimes up to 3/4″ away from the glue in every room. (2) where the butt joints come together throughout the house, one of them would bounce when stepped on (1/32″) while the other end of the butt joint is rock solid. This is appeared immediately after installation and still present 2 weeks after installation. Not likely going away. This occurred in 50% of all end joints. (3) Along the long length of the engineered boards (longest is 8′) where the tongue and groove is at, some are even separating (meaning vertically not horizontally) to where no fillers can stay in because movements break up the fillers to pieces.
While there’s theories on how this happened (and none the installers would admit), bowing in the middle of the walll area due to excessive strapping/clamping without weigh down, bouncing joints because of excessive walking around during installation of floor, etc… We now have to fix this. We tried to remove one piece and it tore the heck out of the wood, which means the glue is working. So floor removal is not an option. One option is to drill an 1/8″ hole and inject a needle of 2-part epoxy to all bouncing sections and glue the boards together to each other at the tongue and groove areas to lock them together before swedish finish is applied. I dread having dozens of tiny holes visible in every room (matching fillers will only do so much to hide). Is this a good approach?
Can you guys give some advice on what happened to the floors and how would you fix it?
Replies
Could the flooring material have been stored at a different humidity than where it was glued down? It sounds like shrinkage, but, with an engineered floor? those usually are stable, unless some water is getting underneath.... Saw a floor look like moonpatrol after a month when it was put over a dirt basement. dehr..
thats a stinker...
I think the wood is fine. Mfg said no acclaimation needed, but it got 2 weeks of acclaimation anyway waiting for scheduling. No water. No heat change. 66 degrees in house for 3 months.
Streamline,
I would be surprised if glueing engineered (or any wood) directly to gypecrete was an acceptable practice. Gypecrete can give off a lot of water as it cures.
You mentioned no water and 66 degrees...what about humidity?
too much moisture and wood not good
Edited 3/23/2008 2:05 pm by homedesign
Agreed. I don't think there's any good way of gluing to gypcrete. We are about to do a floating floor over gyp, but AFAIK the glues are designed for concrete slab installation, and it's a fairly new method.
After we poured our gyp I got a dehumidifier and ran it for quite a while. It's like pouring a couple hundred gallons of water on the floor.
I am with Homedesign and David, I think it is the gypcrete, You don't say if it is a solvent or H2O based glue, but the flooring is engineered you have different plys in running in different directions, moisture hits a board and it can bend because of gain direction. Same way a sheet of cdx does not always lay flat. How long was the gypcrete down, did it get a moisture test, the way one would a concrete floor, square of plastic taped down for a day or two? Aside from that I think is is a compatibility issue between the two, a lot of moisture in gypcrete. BUt you have a lot going on floor, sub floor, gypcrete, heat a lot of stuff going different ways.For any one else reading this the preferred method would of been to float the floor, on a pad perhaps ( some argue you lose heat because of pad) Idea if glue is tacky could a vinyl roller be ran over it) with protection on the floor to set the edges?Wallyo
Could be some ends are missed milled grove bigger then tongue, If injecting how about an expanding glue like gorrilla glue and a hypo needle, the smallest it will pass through, need weight over night. A close up photo of the problem would help us if you can.Wallyo
Edited 3/23/2008 6:16 pm ET by wallyo
The gypcrete was installed last summer and heat has been running for several months now so I don't think it's a moisture issue. I think it's the installation issue where the floor was strap clamped too tight without weight down so the center of the room buckles. The butt joints moving independently, I think it's the walking around on the floor during installation caused the glue to ooze away when the wood is not touching the gypcrete (tongue and groove are have a little play in them on this engineered floor). What do you guys think about drilling down 1/8" hole and inserting a needle of 2-part epoxy to lock the tongue and groove together? Has anyone done this? The house is quite dry now as it is winter and the floor has been heating for several months, though we did not do a moisture or humidity test. There is a 1/2" space all around the edges as I have 1" base boards coming in.
I wouldn't do anything until you talk to the flooring manufacturer to find out whether glue-down to gypcrete is going to work at all.
This may sound crazy, but can the radiant heat pipes be located with some sensor, such as one used to detect heat loss? Get the floor to go cold then turn on the heat and see if pipes show up.
Then use concrete screws and try best to cover with equivalent caps so maybe the planks look like they were fastened and capped.
I tried using epoxy in a different situation, and I think they don't hold well when you can't see the joints or used in small, controlled amounts. Hope this helps.
The glue used was it one by or recommended by the flooring manufacture? Under the board you tore up was the glue set or still tacky? I still would inject a urathane glue before an epoxy. Try a sample area try both types but it may be time to call the floor supplier or manufacture.Wallyo
the glue pulled up was tacky and it has been a week when we pulled up. that's the nature of this glue. The glue is mfg recommended. I will try poly glue to see if that may yield different results. Trying to get the floor distributor to come out to assess w me. I don't think I want to pull these planks. They defeat the purposes and there's a chance I may hit the pipes below.
StreamlineThe reason I asked if the glue is tacky goes back to the weighted linoleum roller idea. I have no idea if it would help but if you rolled the thing would you be able to get the raised parts set like laminate and contact cement?Wallyo
Our floor guys put a vapor barrier over the gypcrete, then 3/4" ply floating, on a diagonal, then engineered floor
You didn't say if you left an expansion space between the flooring and the wall.??