HandymanUSA — Misc Floor Questions and Answers

HandymanUSA - Misc Floor Questions and Answers

Floors Sagging towards Outside Edges

I recently bought my first home. It is an 1870’s farm house. The previous owner sprayed foam insulation on the outside of the foundation. The foundation appears to be in good shape, looking from inside the basement. But, the floors on the first floor are sagging towards the outside edges. The center of the house and the second floor seem level. Help!

I guess I wonder how bad are they sagging, and why. A lot of old homes don’t have a level floor anywhere in them. Part of the charm.

But you should check that structuraly the outside walls, the sill beams they used are still in good shape. they have not been eaten up by termites.

It is possible to jack up the walls, and add wood or stones to level (sort of) the floors. But often this can create havoc with the plaster. But if the wood in the frame is all in good shape, it can be done. and if you don’t move the walls up too much, the plaster may not crack, or not crack much.

Fixing Unlevel Flooring

My first story floor is unlevel due to some settling in my basement (a supporting wall in the basement had actually sunk around 1). I have confirmed with a structural engineer that the settling should no longer be a problem due to correction of outstanding draining problems along the foundation.

We are looking to remodel our kitchen (on the first story) and want badly to relevel the floor. There are several dips and undulations in the floor ranging from 1/2 to 1+ in depth.

I’ve had a contractor out to give a quote for the job and he insists that I would need to remove the old sub-floor, install new joists, plywood and Hardi-backer sub-flooring that would provide a straight (but not necessarily level) floor to install the new ceramic tile over. His rationale is that this is the only true way to correct the problem and would ‘protect’ me if the floor does ever settle again.

My sense is that I would be able to add plywood to areas where the undulations are the most severe and fill in the remaining areas with self-leveling compound. I would then install 1/4 Hardi-back over the old subfloor and areas that I had leveled with the leveling compound to provide a smooth floor to install the tile over. Thoughts?

Getting the subfloor back to it’s original level is the ideal way of dealing with this but your method will work. There are self leveling compounds that will do the trick. But remember the cabinets are sitting on this same unlevel floor. The best idea is to gut the whole room, then level the floor.

Warped Floor Joists Creating Unlevel Floor

I have 2 floor joists that are warping up in the kitchen floor. The basement ceiling is finished, but I cut a hole and found out there are no cross piece supports between the 2 joists because of plumbing and air ducts running between them. How do I draw the joists back down to make the floor level again. The rise is about 1 1/2 and is unsightly in our 4 year old house!

1 1/2. Yikes! Blocking/bracing isn’t what is causing this nor will it correct it so don’t worry about this. There is no easy way of fixing this problem (especially the severity) without some extensive rework (that I know of). You are probably going to have to take up the finish & subflooring in that area and rip or plane the offending joists to get them on the same plane as the good joists, lay some new subflooring & try to patch the finish flooring. I’m curious though if the floor had this condition originally or if it developed over time. You made mention of duct work and such in these joist bay, I’m guessing the lumber was VERY wet and has over time dried and warped (typical). Regardless, I don’t think this is going to be an easy fix. Note if you choose to do this yourself, accurately locate the joists, snap a line on the CENTER of the joists, set the depth of the saw for total depth of flooring and cut. You need to make certain that half the joist is available to lay the new subfloor on.

Sagging Floor in Center of Room

The floor in one of the bedrooms of my house is sagging approximately 1″ in the center of the room. The house is built on a pier and beam foundation, and all of the beams seem to be in good condition. what would you suggest?

You don’t provide enough info to answer..

However, if the piers and beams are level, it could be the floor joists themselves simply sagged over time. Not unusual if the span is too great for the size lumber used. Not much to correct the problem but to jack up the center of the floor and run some extra beams at mid point in the floor.

Fixing Sink Holes in Floor

I have an older mobile home that has had water damage to the particle board floors. I want to put down new floor tiles in kitchen. Can someone tell me how to make the sunken areas level first. What can I use? I cannot replace the floor, just want to level it.

Any place that sells flooring or even the home centre has a cement based leveling agent you can use. Just follow the directions. It is called a leveling agent and is made for over sub floors and such just as you need.

Removing/Replacing Dryrot in Flooring

After fixing the valve/o-ring in the shower handle, for the 3rd time, I realized on the floor adjacent to the bathroom was wet/damp and with dryrot. I’m not sure how much flooring has been damaged. what steps do I need remove and replace rotten wood floor?

Sort of a big job. What is on the floor now? You would have to pull that up and check the subfloor and underlayment. Then cut out what is rotten. If you cut along the center of a joist, you can mount the new subfloor/underlayment where the old stuff was removed. (you can cut along the top of the joist with the saw’s depth set for right at the thickness of the subfloor you are removing.)

After replacing the subfloor. comes probably the harder job of matching up the old floor, or more likely redoing the whole floor.

Replacing/Repairing Rotten Floor around Toilet

I have rotten wood around the toilet in the bathroom .It looks as if has been repaired before. What do I need to do. Also do I need to sand the floor down before installing the the new linoleum or is there an easier way ?

First, make sure you have fixed the leaky toilet. If you have, then replace any of the underlayment and subfloor which is rotten. Cut to the center of the joists so the new plywood will have joists to rest on. Don’t end both layers in the same spot, overlap them a bit so the seams are covered. On the rest of the floor, if you have the vinyl up already, it may be easiest to replace the subfloor in the whole room, or cover it with 1/4 luann plywood. You do need the floor to be perfectly flat before laying the new vinyl down because every bump will telegraph through. Sanding and scraping may work, but remember you want the floor as flat as possible.

Best Way to Find Floor Joists?

If seeing the exposed joists isn’t an option how do I find them.

You can use a stud finder. It should work on floors and ceiling as well.

Sistering a Floor Joist

The inspector of our new house says a floor joist should be sistered to strengthen it from termite damage. Should I nail a new one directly to the old damaged one, bolt it on, attach it?

Well, sistering implies just running it parallel. Bolting or nailing the two together helps transfer any weight born directly by the bad one, from say a wall above to the new one. This is easier than removing the bad one, and is typically the way to go. There may be numerous nails from walls and the subfloor above in the old one, so leaving it in place will leave all these nails intact.

OSB Board & T&G Subfloor

What’s the purpose of OSB board and can a 3/4 inch tongue and groove be used as a single layer of subfloor/underlayment?

OSB or Oriented Strand Board is a substitute for plywood. It is no better than plywood so if you would only use 3/4 inch plywood, then 3/4 OSB may be substituted (in most instances) It is generally cheaper, so that is why its use is increasing. For subfloor/underlayment, it depends on what you will be putting on top. If you are putting solid hardwood floor down, then that is enough. If you are putting down vinyl or carpet or tile, then use should use 1/2 plywood as an underlayment on top of the subfloor of OSB.

Pressboard Sub-Flooring

Our washer has leaked on our main floor and bubbled our press board sub flooring. I believe there are two layers above the joists. The first being plywood and the second is pressboard. How do you cut out the top level (pressboard) to replace it?

HandymanUSA - Misc Floor Questions and Answers

Are you sure you have two layers? Not all homes have two subfloors due to cost cutting. In any event, you can cut out the damaged subfloor using a circular saw set to the thickness of the subfloor wood/fiberboard. Be mindful of nails or screws when you are cutting!

You will have to cut to the nearest floor joists from your damaged area (this is so your can attach your replacement piece to the joists for structural integrity and to reduce of floor movement) Cut your repair piece to fit and screw it to your floor joists. Cover the repaired area with whatever product you presently are using on your floor.

Mostly likely your old subfloor is simply nailed or screwed in place so it will be easy to remove but, sometimes they are glued as well, so you might have to use a pry bar to remove it. so, be careful that you don’t extend your work area by overzealous tearing up of the floor.

Replacing Stair Surfaces

I live in an 80-some-odd year old house and I am thinking about doing work on the stairs to the second floor. In particular, I would like to remove the stair surfaces (and maybe the risers and rail) to do away with old, worn out wood that is layered in paint (some lead I suspect) and replace with a nice wood that I can stain. I need someone to confirm just how insane I am and give me an idea of how ambitious this project is.

Stair parts can be purchased from good lumber yards and they me in a variety sizes which likely will cover your opening. Parts may have to be ordered. Stair parts are expensive too. Scope the whole thing out. Find a place to buy the parts. and see what they cost. A single oak tread goes for around $35. You may only want to do parts then.

Small Crack in Slab a Problem?

When replacing some carpet in a house I recently bought, I noticed a small crack in the slab running near the base of a wall. It looks like it’s about 5 feet long, but might continue under the wall. It’s about 1/32 inch wide at the widest point. Do I have a dreaded cracked slab? Or are small cracks like these to be expected? The outer edge of the slab looks fine, and none of the doors sticks at all. Anything I can do to minimize the chance of this crack expanding? The house only has gutters on the front and back, not the sides, would putting in gutters help keep the ground from shifting?


Concrete cracks, even under the most controlled circumstances. Builders add ‘control joints either by cutting a small channel with a concrete saw, or by running a double edger through wet concrete. Control joints ‘control’ where the cracks occur.

In single slab pours, it is not uncommon for no control joints to be added, particularly in basement slabs where a glass finish is desired. There is no structural problem. What you are experiencing is normal and is of concern. If it makes you feel better, fill the joint with some concrete caulk or some hydraulic cement and go to sleep knowing all’s right in the world. -)

Marble Floor Finish is Dull

we’ve just bought a home where there is marble tile in the kitchen and bath. It appears dull and porous rather than shiny as you would expect. Any suggestions for how to fix?

It sounds like it was not sealed.

Here is a link to some cleaning and care tips.

New House Floor Bounce

Our house is 1.3 yr. old and we’re not happy w/ the bounce in our first floor kitchen. Floor joists are 2x10s on 16-inch centers over a full unfinished basement. Joist length is 13.5 ft. Wood X braces between joists were installed at 7 ft. What’s the most cost effective way to stiffen the floor. Would installing additional 2×10 blocks between joists help or should a 2×12 be nailed to every other 2×10 joist ?

I guess I would ask that you clarify bounce. If as suggested ,it is movement in your subfloor and/or underlayment you feel it is one problem. If it is a total floor bounce, you are feeling that is something else.

A 2×10 joist on 16-inch centers on a 13.5-foot span is a good solid floor. Well within acceptable. Solid blocking does a better job then diagonal blocks. Adding them would help. You can try that first. But I don’t think you will see that noticeable a change. If those 2x10s don’t suffice for you now. Adding 2x12s maybe the way to improve it to your liking.

If you are only feeling the floor give a little under your feet. it may be that it is only your subfloor moving down to the joist.

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