Glued Engineerd Floor to Gypcrete Failed
We had our 3/4″ Moabi hardwood 7″ wide plank engineered floor glued to gypcrete above my radiant heat floor. The glue was Parabond Millenium Series 2004 Premium Plus for engineered floors. This was done in March ’08. Today, I noticed 2 boards butting tight up against a slider door (with metal threshold) are coming up. I am seeking advice on how to identify the cause and repair these 2 boards.
There are no water or moistures detectable. I wouldn’t think there’s any because we have a door pan underneath the slider door (custom made with sheet metal) plus a full tube of caulk under each door. I would rule out water or moisture. I suspect one of 2 causes:
1. It is the installation work itself as they clamped all the boards together too hard and bowed the end boards to which the glue did not effectively attach. They had to fumble with that later with heavy blocks to hold down the pieces, but I wonder if the damage had already been done during the installation stage and the glue was already ineffective by then. This is probably the lesser of 2 evils problem because we can drill an 1/8″ hole, inject epoxy to re-glue and solve the problem.
2. Or, the floor expanded with radiant heat being on and since there is no room to expand against the metal slide door threshold side, it buckled up causing the first 2 boards against the door to pop up. This is not good because the boards now will have to be lifted (along with everything that is in its way (door casings, refinishing with swedish…) so an expansion gap can be cut against the metal door threshold. The thing is there are other rooms in the house with the same wood-against-metal-threshold situation but the boards are intact. I don’t want to cut an ugly gap strip unnecessarily if this isn’t the cause.
By the way, the 2 wood strips that lifted are 15′ long running the full length of the room, but butting up against the metal threshold is only 6′ (i.e. the door is only 6′ wide). The remaining 9 feet the engineered floor butts up to drywall with a proper 1/4″ space between them. So, one would think that with that gap against the sheetrock present, it wasn’t the wood expansion that caused the lift.
The temperature has been rather constant and we are very mindful as to not raise radiant temperatures more than 1 degree a day. Of the 1500 sf of flooring, these 2 boards are the only problem children. I would appreciate your thoughts, ideas, and repair suggestions.
Replies
With the radiant heat on the floor would more likely shrink than expand (less relative humidity = more shrinkage). Engineered boards should not shrink as much as solid wood. 7 inch seems wide for a gluedown installation - what did the manufacturer recommend?
Is there glue under the boards that are coming up?
Was a primer used on the gypcrete? This is very very important and even if you used it it does not guarantee that it will result in a long life installation. Gypcrete is #### for anything excepting a floating installation.
Does the glue manufacturer warrant their product for installation to gypcrete?
primer/sealer for gypcrete is up there in the critical mass realm...
without it a lot of "things" won't go according to plan...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
Forget the primal scream, just ROAR!!!
The mfg says the engineered floor is designed for glue down, and sells the glue on gypcrete. It's a blame game now. Installer blames the product, product blames the installer. No accountability as usual. It was not sealed as the floor guys says unnecessary. I guess I should researched more rather than listen to the expert.
The glue manufacturer should provide a specific set of instructions for gluing to gyp, and the installer should follow them... and you should ensure that everyone is doing everything by the book. Who brought the glue to the job?
sometimes the gypcrete can get chaulky... and it's supposed be sealed. Either will effect the adhesion of the mastic...
Gypcrete needs to have some kind of membrane for adhesive to stick. I used a product called Blue devil that was a roll on membrane colored blue.. I installed tile over that and have not had any problems. I did remove a tile once after a few days n the gyp came up instead of the membrane. I have seen a red roll on membrane too but I don't know the name of the product. Even PL 400 will not stick to untreated gyp.
The red roll on stuff is probably Red Gard from Custom Builders.
Could it be your water temp? What are you running it at?
I would fault the installer. Gypcrete has never been a product to direct glue to, although some glue manufacturers say if the strength is 3000 PSI and higher it's safe. Not familiar with the adhesive mentioned but Bostiks has some info.
http://www.bostik-us.com/tds/TDSFiles/BostiksBest.pdf
Mines fine to date and it was installed per the manufactureres data. Maximum temp was a key element as was the prep. It's all in the details. I used the same product you posted a link to.
Edited 10/9/2008 9:15 pm ET by RobWes
I see a few problems here.
-I'd double check that 1/4'' expansion gap in the mfr's instructions.
-I'd also take a toe kick saw or rotozip to the section at the sliding door and give it proper expansion. (the rotozip sucks, but works for this)
-If Gypcrete says to seal it, then...
-I was more than pleased w/ Millenium adheasive. It spreads very easy and has a low odor. I prefer it over Bostik.
- If the floor had to be weighted down, something is not level (unless see below). It should have been rolled too. Did they use a roller?
- Many times i've seen wood that was warped and creates the same effect as an unlevel floor.
You have an easy fix because the problem area is at a wall. Post pix.