Floor leveler question
 

I'm redoing a basement apartment and am putting down laminate flooring. (used to be carpet). It's a concrete floor. Most of it is flat except for one section near one wall. It's about 8' long and maybe 4' wide and dips down about 3" possibly more. I'd planned to just use floor leveler until I looked at the price--$30 for a 50lb bag. I'm guessing it will take 8-10 bags to fill in the dip. Then a thought occurred to me--why not just cut up some treated 2x4's to fill most of the dip and then pour floor leveler over the top of the 2x4's to smooth if off. Would save a lot of money and I can't imagine why it wouldn't work. I'm just looking for a flat enough surface to put the laminate on. It doesn't require the strength of solid concrete. Thoughts?

Had another thought--concrete pavers instead of 2x4's.

Just realized wood probably won't work unless fastened to the concrete because it will float in the leveler.

Use inexpensive concrete for the lions share of the volume then top with leveler. If you are real good with crete just do that right for all of it.

I have used the leveling products before. They work well, but make sure you mix it thin enough to flow out well. Probably more water than the package calls for. If you don't you will end up with too much height on the floor.

You can use concrete mix to get it close to the height you want but you need to use a bonding agent for it to adhere to the existing floor. Add some extra Portland cement to the concrete.

Thanks. Today I found some 2" high paving bricks and I was able to put about 50 of them in the deepest part. I'll use concrete to build up around the edge of the bricks, getting it close to the height I need, then put the leveler on top of that.

Here's what it looks like.

Are those pavers set in mortar?

If not they should be. Any movement in the substrate will cause your topcoat (whatever it may be) to fail.

Fill the majority, 98%, with a quick set concrete (Fascrete 5000 is good product) in several lifts and allow to dry/cure (a minimum of 72 hrs-7 days is better) then use a good self leveling cementitious product (SilPro products are the best IMHO) and again allow to cure for a minimum of 72 hrs. then install whatever surface you desire.

Do not fill with pavers and cement-you need to lock into the existing substrate which the pavers will not do.

Do not embed timbers or joists as they will rot (PT or not).

I oversee floor repairs/renovations in NYC schools that date from 1871 to 1995 and have seen what works and what does not. I have the benefit of looking at what has failed in the past as a guide to what to use in the present.

Rule 1-If it is the cheapest product on the market, there is a reason...usually the components are garbage.

Rule 2-If you cannot get the manufacturers rep on the phone 24/7, do use the product. My work is always done on nights and weekends...

Rule 3-Do it right. Do it once.

Not yet but they will be.

Stoney, I took your advice, returned the pavers and bought 10 bags of fast setting concrete. I'll put that down this week and when it cures, put the leveler on top of it.

Did you hear about the NYPD Academy flooring debacle?

High-tech floor at new NYPD academy is already falling apart | New York Post

(And spending $750 million on the thing reeks of corruption, considering that the construction cost of #1 WTC is something like $3.9 billion and is a much larger engineering project.)

This is a prime example of do it right the first time vs 'value engineering'.

Stoney said it right....good decision.

Got the concreting done. Looks like I should get a job as an estimator. Estimated 9 50lb bags and hit it right on the money.

Looks good!

8 years ago I quit the firm that did the Construction Inspection on that job...now you know why. 2 people who were involved in Structural Inspection on that job quit because they were pressured to look the other way on major issues. I helped them find jobs elsewhere.