Leveling a 100 year old house floor...

[joshunger]

I'm working on a 1904 house which still has the original 1x4 fir flooring without a subfloor. The decision was to salvage the fir flooring (never sanded), remove, level, and add a subfloor. Side note, the floor is in great shape except for the kitchen sink ... which is worn down just under 1/4", interesting.

This leads to a couple of interesting questions that I haven't found exact answers to in the forums.

1. What is the generally accepted slope / out of level for floor joists for an older home that does not need to be leveled? So, x over 24" inches or some distance? For example, is 1/2" over 24" inches acceptable and/or noticeable by most? My conclusion was around 1/8" to 1/4" over 24" as long as the 1/4" was leveled into the next 24" inches.

2. We reinforced the joists from below, but they still need to be leveled. I see a couple of options -

(a) ripped shim / 2 x 4 on top of the existing joist - seems to work well for 1/8" adjustments that are even. Was mentioned on an older post.

(b) 2 x 4 sistered

(c) Larger 2 x 6+ material sistered - this seems to just waste lumber as the joists have already be reinforced?

Any opinions on when to use each approach?

The joists in this house are 2 x 8.

Thanks.

-josh

[David Meiland]

Re: Leveling a 100 year old house floor...

If the floor needs to be leveled, why doesn't the house? I would get underneath it, jack it up level, and shim it to the foundation. Then the floors and everything else are just about where you want them.

[joshunger]

Re: Leveling a 100 year old house floor...

If the floor needs to be leveled, why doesn't the house? I would get underneath it, jack it up level, and shim it to the foundation. Then the floors and everything else are just about where you want them.

Yup, we did this on the corner of the house that was significantly out of level. The remaining joists that are not level are mostly out of level in the middle of the joist span... they've sagged slightly over 100 years even though an acceptable span.

[David Meiland]

Re: Leveling a 100 year old house floor...

Ahhh, got it. If you need to plane the tops, I would do it with shims nailed to the top of each joist. You may have to do some tedious ripping of tapered strips, curved/tapered strips, etc. Glue them on with construction adhesive and maybe use a few small nails. When you re-install the wood floor, nail all the way into the old joist material.

You can do this by nailing new 2x next to the existing, but it makes it harder to install insulation nicely, so I wouldn't do it that way.

[jrrjrr]

Re: Leveling a 100 year old house floor...

screw a straight 2X6 to the old joist 1/8 " above each end of the old joist with a jig saw saw along the top of the old joist start in the center sloping the blade to the old joist to start then go back and go the other way glue to the top of the old joist with a few brads to keep it on now rip the 2X6 so both sides are parallel repeat this to all joists the floor will be straight across but not level if the top plates are not level jrrjrrr

[TSJHD1]

Re: Leveling a 100 year old house floor...

My conclusion was around 1/8" to 1/4" over 24" as long as the 1/4" was leveled into the next 24" inches.

1/4" over 2 feet is too much. You will easily feel that underfoot.

Tom

[S.Joisey]

Re: Leveling a 100 year old house floor...

A laser level has made his job easier for me.

Set your laser at joist level,screw a 2x to the side of the joist with its top on the laser line.Scribe the 2x to the joist, unscrew it, then cut to the line.

You can screw this piece to the top of the existing joist, and power plane any humps.

Start with the joist farthest from the laser so you don't get in your way. With a bit of fussing,I generally am able to get a floor to tolerances of the width of the laser line

[kfc510]

Re: Leveling a 100 year old house floor...

A laser level has made his job easier for me.

Set your laser at joist level,screw a 2x to the side of the joist with its top on the laser line.Scribe the 2x to the joist, unscrew it, then cut to the line.

You can screw this piece to the top of the existing joist, and power plane any humps.

Start with the joist farthest from the laser so you don't get in your way. With a bit of fussing,I generally am able to get a floor to tolerances of the width of the laser line

Why not just palm nail the 2x to the side of the joist once it's at the right level? Seems like a lot of work to scribe it and nail it on top. What do you find is the advantage?

Also, back to the question of what's acceptable- frankly, on a 100 year-old house, 1/8" per foot seems very acceptable to me- most people wouldn't even notice it. I'd never suggest correcting that kind of settling unless the client already was clamoring for it, or it was necessary to make some other phase of a project work. Many really nice old houses here are wonky waaay beyond a 1% slope, and most folks don't seem to care.

kevin

[David Meiland]

Re: Leveling a 100 year old house floor...

Kevin, it's hard to do a good job of insulating a floor with stuff sistered irregularly to the sides of the joists, which is why I do rips on top.

[dgbldr]

Re: Leveling a 100 year old house floor...

David, he didn't say it was on crawl. If it's on basement, no insulation to worry about.

To the OP: Acceptable is what the client demands. I have a room in my house that's 1/4" off in 12 ft. It bothers me. My wife can't tell the difference nor would she pay a penny to remedy.

The way we do this is to jack all the joists level, gradually, then a bit "over" for spring-back. Then sister with equal size lumber or 1/4" steel plate. screwed (or bolted, respectively) and glued. Leave jacks on for a couple of months and un-jack gradually. Works well and stiffens the floor also.

Edit: You didn't say what "we reinforced" means, but you should have had an overall plan before you started, the "reinforcing" may restrict your choices now.

[kfc510]

Re: Leveling a 100 year old house floor...

Kevin, it's hard to do a good job of insulating a floor with stuff sistered irregularly to the sides of the joists, which is why I do rips on top.

Fair enough. Here in the Bay Area I'm content to stuff the batts into the irregular 13" (+/-) space and call it good, but I can see that might not be ideal everywhere.

kevin

[David Meiland]

Re: Leveling a 100 year old house floor...

David, he didn't say it was on crawl. If it's on basement, no insulation to worry about.

You might think, but on the occasions that I see a basement here, it's usually unconditioned and the joists are insulated. From living in Michigan 25 years I know y'all have a lot of basements with no insulation anywhere.

[kfc510]

Re: Leveling a 100 year old house floor...

To the OP: Acceptable is what the client demands. I have a room in my house that's 1/4" off in 12 ft. It bothers me. My wife can't tell the difference nor would she pay a penny to remedy.

I doubt more than 10% of the rooms in all the houses in my immediate local are within 1/4" over 12 feet! Seriously, I go to a lot of open houses, and I'm often tempted to put a marble on the floor, just to see the realtors' face. I behave myself though, if I comment or ask about it, it's always quietly and when no prospective buyers are around.

I don't hear anyone else discussing it unless it's very radical, at least 2%. (It's often much, much worse, and even then it doesn't seem to be a deal-breaker, or anything that generates much fixing in and of itself). Of course, the housing stock out here is older, and the really nice areas are in the hills, so a certain eccentricity is seen as part of the good life, I guess. People accept all sorts of things to be in a nice old craftsman in the hills.
k

[David Meiland]

Re: Leveling a 100 year old house floor...

Sometimes it's hard to tell what has settled and what was simply built out of level. We just finished a remodel, house from the late 70s, the floors went up and down all over the place. They didn't have lasers in those days, and I bet the original builder of this place used a 4' level, or maybe one of those little 2" levels that hangs on a string.