Dip in subfloor during hardwood floor installation

Hi,

I'm trying to put in 3/8 inch engineered hardwood flooring myself, and would like some help.

We have 3/4 inch OSB as our subfloor in our bedroom upstairs. On some advice, we started to nail 3/8 inch CDX plywood to add some more structure to the subfloor. We chose 3/8, so that we would be level with our bathroom flooring.

While nailing down the plywood, we noticed that the floor dips downward towards the entraceways to the room. Starting about a 1.5 feet before the entrance to the bathroom as well as the hallway, the floor starts to dip, reaching a depth of app. 3/16 of an inch at the doorway of the bathroom and hallway.

The hardwood, once installed, will run lengthwise into the dip.

How do you go about leveling the dip? Is it something we should be concerned about? Any advice will be greatly appreciated.

Reply to
ksanny
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Look for a product called "Floorstone". It usually comes premixed, but I have seen similar products at the BORG as a powder that you mix with water and trowel on to level the subfloor. Look in the vinyl flooring section for it.

Reply to
Mark Hopkins

Thank you for your response.

Can you tell me how this might work, as I am somewhat unclear on this?

I have the plywood nailed down onto the OSB. Do I pour on the leveling product on top of the plywood, and then install the hardwood on top? Will I be able to staple the hardwood thru the levelling product?

Reply to
ksanny

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've used this product many times. It works very well.

Dave

Reply to
TeamCasa

I had a similar problem when I was putting down 5/8" engineered flooring in my dining room. I tried using a leveling compound to fill in a few low spots. However I wound up removing the compound as I felt that it might break apart in the future and cause another problem, especially since I glued down my flooring. I was told by Bruce Flooring that if I wanted to put down a new layer of plywood, that it had to be 3/4" inch thick or they would not warranty their product. Since the 3/4" of the new layer plus the 5/8" of the flooring would have raised the level of the flooring up over 1

1/4", we decided not to put down a new layer of plywood. What I did was to rent a floor sander with a very agressive sandpaper and sand down the high spots. It doesn't have to be perfect but you should get at least a four foot straight-edge and make sure that you don't have more than about 1/8" gap under the straight-edge as you sweep it around the floor.

So far it has worked out OK.

Rich Durkee

Reply to
Rich Durkee

With a dip of only 3/16" i would build up the low spots with several layers of tar paper. Start with a wider strip and feather the layers inward, building up layers as the floor dips, until you get the floor flat. Using self leveling floor lever is another option, another post recommended ardex. This stuff is WONDERFUL for leveling a floor, but for 3/16" it may prove to be more of a hassle. Plus, with tarpaper, you can fasten through it to your ubfloor. --dave

Another post suggested ardex. this is WONDERFUL stuff for leveling a floor, but for the amount you need to fill, it would be difficult.

Reply to
<daveandfritzi

I would put it down before installing the 3/8 plywood but you can do it either way. 3/16" is not that much so there should be no problem stapling through it. Just make sure you get it mixed to the right consistency (much like pancake batter) and work it out nice and level. Let it cure and you should be all set.

Reply to
Mark Hopkins

Virtually every commercial installation has leveling compound under it. I wouldn't worry about it at all. Even if it cracks up it isn't going anywhere, after all, it's already in the low spot - right?

Tim Douglass

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Reply to
Tim Douglass

Thank you all you wonderful people for your advice.

I just discovered I face another problem, that I'd like to ask your advice about.

Going along with the felt paper layering idea, I was playing around with how things were going to look like, when I realized that if I attempt to level the dip and then put my flooring on, the door to the bedroom does not close anymore.

So now I'm sort of stuck. Do I level the floor and then put the flooring on and then cut my hollow core door to size, or do I just leave the dip and put the flooring on, in which case, the door with close?

The wood flooring will run perpendicular to the door frame when installed. The dip is app 3/16 inch at the door entrance.

Any advice is greatly appreciated.

Reply to
ksanny

D'oh!

Yes. The hollow core door should have at least several inches of solid wood at the bottom of it, so you've got room to do just what you are about to do. Make the floor right, then make the door right to work with the floor. Leaving one thing wrong to make it fit another wrong thing ends up being a disaster after not too long, those sort of things have a habit of accumulating.

For 3/16ths of an inch, you may have found an actual use for an electic powered hand plane. Or, sawhorses and the skilsaw.

Dave Hinz

Reply to
Dave Hinz

Yes cut the door, you should have more than a inch of solid wood at the bottom of the door but when you cut it take and take a knife and cut along the line and when you use the saw to saw to cut the door it won;t fray above the line giving you a nice clean edge.

Reply to
Brian Morris

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