Slab extension settled/settling, looking at options, risk in refinishing wood floors.

[JDS]

Hello,

I recently bought my first house here in Seattle. It is old, 1941, and has had a few extensions and modifications done to it through out the years. One of these modifications is a extension to the house that is on a slab extending out from the foundation. There is a section in the wood flooring that is high centered where it crosses over the foundation and onto the slab section of the house. You can see it clearly in both rooms that are extended onto the slab. There are also cracks (that someone has attempted to fix) in the wall and ceiling.

One of the first projects I was going to do is refinish the hardwood floors in both of these rooms. I am worried that finishing the floors first is putting the cart before the horse and I will end up wasting the 20 hours or so it will take me to refinish them if I am later required to somehow repair the slab (mud-jack?).

My questions are:

1. If the extension is 10+ years old (looks at least that old) is there much of a chance that it is still settling?
2. If it is done moving, could I just re-level the inside of the house?
3. Would getting the extension "mud-jacked" required ripping up the hardwood floors to get down to the slab and drill holes?
4. Does it make sense to use a non-poly based finish for the floors (like waterloxx?) so that I can spot-refinish the floor if the slab is jacked later?

Thanks in advance for any advice!

-Justin

[trader4]

"I recently bought my first house here in Seattle. It is old, 1941, and has had a few extensions and modifications done to it through out the years. One of these modifications is a extension to the house that is on a slab extending out from the foundation. There is a section in the

wood flooring that is high centered where it crosses over the foundation and onto the slab section of the house. You can see it clearly in both rooms that are extended onto the slab. There are also cracks (that someone has attempted to fix) in the wall and ceiling.

One of the first projects I was going to do is refinish the hardwood floors in both of these rooms. I am worried that finishing the floors first is putting the cart before the horse and I will end up wasting the 20 hours or so it will take me to refinish them if I am later required to somehow repair the slab (mud-jack?).

My questions are:

1. If the extension is 10+ years old (looks at least that old) is there much of a chance that it is still settling?
2. If it is done moving, could I just re-level the inside of the house?
3. Would getting the extension "mud-jacked" required ripping up the hardwood floors to get down to the slab and drill holes?
4. Does it make sense to use a non-poly based finish for the floors (like waterloxx?) so that I can spot-refinish the floor if the slab is jacked later?

Thanks in advance for any advice!

-Justin "

Did you have an inspection done before you bought the house? The inspection report should have given you some insight into what is going on. It's impossible to diagnose this type of thing without seeing it and figuring out how it was built and what is going on. If it was not built correctly, the slab could certainly continue to sink/crack more, even though it's 10 years old. As for cracks in the ceiling and walls, some small cracks are going to occur in most structures from shrinking/contracting, slight settlement, etc. These aren't structural issues. However if the cracks are wide and continuing to expand, or doors/windows are going out of square, that's a very different story.

Before I did anything, I'd get an expert opinion from a structural engineer.

[m Ransley]

Sure it might settle for 5-500 years. Get an engineer out. Who can answer not knowing soil, subsoil, water table , foundations-footings on slab and house etc etc.

2 different foundations should have never been done.

[JDS]

Yes, I did have an inspection done before I purchased the house. The engineer seemed very competent though he did not even mention that it is on a slab. I think it may have been a mistake on his part, as I did not realize that there was an extension until I measured the floor upstairs and then the basement. Now that I think about it, it might be a crawl space, not a slab. I will have to try and poke around more outside the house (its hard to access that side of the house outside). All I know is that there is an obvious change in the concrete where the extension foundation spaces meets the original foundation. There is a small crack noticible outside, but its pretty small, 4-5 mm maybe.

Maybe I can convince him to come out and look at it for free since he missed it in his original report.

Thanks for the advice!