Friday, April 21, 2017

Sub-Flooring Installed, Waiting for the Flooring…



Before discussing the next steps required in our flooring redo, I thought this would be a good time to explain how the floor in our Tiffin RV was built. The top layer was  composed of engineered tile planks. The engineered flooring rested on top of 1/8” luan hardwood layered panels. The luan panels are on top of 5/8” OSB sub-flooring panels. Under the OSB panels is a layer of aluminum framing members with a thick layer of Styrofoam insulation in between them. Finally the bottom layer is only a plastic vapor barrier.

I mention this to point out that once there is water damage and the OSB layer is compromised the only thing keeping you from going right through the floor is the top layer of engineered flooring! Yikes!!! That is why it is very important to address any major water damage ASAP.


Anyhow after much cleaning of the water damaged area and redundant measuring I finally got some 3/4 marine grade plywood. Notice I didn’t replace it with 5/8” OSB as I prefer plywood over OSB but I couldn’t find any 5/8” plywood. So, on the patch I simply won’t add the extra 1/8” luan layer so it will match the rest of the remaining flooring’s height. After bolting, screwing and gluing the patch in I finally had the subflooring done.

While the subfloor was exposed it gave me the opportunity to investigate some “creaks” we had in the floor. I fixed most of these using one of two techniques. First I removed the self-tapping screws from the flooring that had worked their way through most of the OSB layer and simply drilled a new hole and re-screwed them into the aluminum framing. One creak was repaired by drilling a hole into the OSB layer and spraying a bit of expanding foam into the void below the OSB creating a more solid base for the sub-flooring.

We still have a couple of creaks in the floor which we will just have to live with since I couldn’t solve them. Such is life in an RV! Afterward I had to do another very thorough cleaning before putting down the luan layer. The main reason for the luan layer is to provide a smooth and level surface for the final flooring tiles.


The only real challenge of laying down new luan is the careful measuring required for all the odd cut pieces. It became a puzzle requiring measuring more than cutting if done right. Only one 4x8 foot sheet was able to be used without any cutting and the other three sheets were cut extensively.

I used only a few tools for cutting the luan. Mainly I used my handy Skill Saw with a carbide tipped blade and for smaller more intricate cuts I used a metal straight edged ruler and a sharp Box Cutter. After scoring the wood along the straight edge about three times, the luan will snap off with a clean edge. Each piece of luan was glued down using one of two glues. I used Loctite pl 400 subflooring glue and gorilla glue. The gorilla glue heavy duty construction adhesive was mostly used on the floor patch but when I needed to glue on metal I also used it. Otherwise the Loctite was used the most. It would take about 2 tubes of Loctite for every 32 square feet of luan glued down.


After gluing a luan panel down I would use a rolling pin to ensure that the surfaces were pressed tightly together. I then used the remaining heavy piece of marine grade plywood and laid it on top of the glued down luan panels to ensure they remained flat to the subflooring. After all the luan panels were glued down and dried the next step was to use some Dap Plastic Wood Putty to close any of the larger gaps in the luan panels and to smooth out any knotholes in the floor patch.


With everything ready and cleaned extensively once more time the final step to installing the luan layer was to use some 2.88 inch wide Gorilla Tape to seal all the seams between the luan panels. This creates a barrier to moisture and keeps it from finding an easy path down to the OSB subflooring while providing a flat and even surface for the new flooring we plan to install as the top layer.

So I have done all I can and am waiting for our special order of new flooring to arrive so I can finish this project up! Hopefully Sharon will feel better soon (her cold turned into pneumonia) so we can get out of the RV and do something fun…

NOTE: We are currently in our former home town, College Station until May 7th. Our plan is to replace our flooring and attempt to fit in a little fun along the way…


  1. Looks like is all coming together soon will be better than new. Good luck with the rest and hope Sharon feels getter soon.

  2. Great job John! We wish Sharon a quick recovery.

  3. Well done John! A job indeed to be proud of, I'm sure it'll soon be looking better than new.

  4. Looking good, John! You will certainly be happy with a great finished project.

    Hope Sharon is up and at 'em soon.