Sinking House

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Posted by: from Toronto
1/15/2013 at 2:50:31 PM

On one side of the house a sunk hole has been created in the floor due to an improper renovation carried out in the mid to late 70's. A bathroom was put in and when they were running the new utilities they cut through 2 joists completely. This has caused the side to sink almost 3 inches bringing surrounding joists down with it.

There is only crawl space under the floor joists, some if which are now sitting on the dirt. The brick wall the joists were sitting on is also starting to crumble due to the load.

We are getting a structural engineer to come in and look.

What would be the best way to go about replacing the floor joists?

sinking house
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Date/Time1/15/2013 at 3:31:47 PM


Sorry to hear of your troubles with that botched reno. We hear it often. Based solely on what you described, there are a few issues:

1) sounds like the joists are too close to exposed dirt underneath to start with (rot issue)

2) if joists are hangered onto plates then the floor can come out and joists replaced

3) If joists sit on to top of foundation wall (bricks?) with wall on top of them, then floor may need to be jacked up and new joists "sistered" beside the existing ones

You really need to have a competent general contractor look at that who has experience in this area.


Alair Homes & Renovations

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Date/Time1/15/2013 at 4:35:44 PM

Typically you would jack up the adjacent joists on either side of the cut ones and once level repair the block wall and then slide new joists in and screw of nail to the old ones to get the strength. You should make sure they go at least 4' both ways and the end rest on the repaired block wall.

Inspect for rot and replace as required and if this is an area with dampness use Pressure Treated lumber. Nail patten should be at least 4 nails vertically every 12"'s.

Sounds like your box header board may also need to be cut and replaced which depending on the siding you have shouldn't be too tough. Add a double joist hanger to the open end of the splice.



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Date/Time1/15/2013 at 4:42:54 PM


First, they should never have cut through the floor joists as they are the foundation for flooring and everything above.

The joists can be jacked up and sistered (attaching a second joist to the cut one) ... if space allows.

You are wise to get the advice from a structural engineer. It may not be a big issue to correct but make sure it is done to code.

Sorry to hear about this, it shouldn't have happened.

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Dolphin Construction Co. in Ottawa
Date/Time1/16/2013 at 9:49:52 AM

If your getting Structural Engineer on the site, he will recommend solutions for your problems and you better stick to it and do what he recommends, anything else is a bs.

Then hire somone who can follow his recomended scope of work.

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Date/Time1/17/2013 at 10:18:07 AM

You will want a structural engineer to examine it.

But I would suggest the following to any client of mine. First, any floor joists and supports should not be on brick. There should be a proper cocrete foundation poured from the weeper tile around the structure to the level line for the first floor. Then construction plastic should be applied and a 2"x6" plate should be bolted to the concrete foundation. Then all floor joists can be laid and nailed to this plate. If it were my house. I would go this route.

This will be costly, but if you plan to live there a while, it will be worth it.

I have read other posts regarding repairs, and some are possible. But you will have further issues in the future.

Good luck with it.

James Fram

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Date/Time3/28/2013 at 11:09:46 AM

Sounds like you need some underpinning too in addition to all the other comments. Get a structural engineer and remember it's always cheaper to do it correctly the first time.

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