joist sag?

[trexxxmeister]

I am a novice DIYer who is renovating a second floor bathroom. I removed the subfloor to move some pipes and now that I am ready to relay the subfloor I have discovered that one of the joists ( which are 16 inches apart) and which is in the centre of the room has sagged an inch. It has sagged where the first floor chandalier was attached. I removed the chandalier and tried to pull up on the joist but it won't budge.I am limited as to how much I can push up on the joist from the first floor because I dont want to disturb the finished ceiling.

When I lay plywood across the joists there is an inch gap between the plywood and the one joist. I could proceed and screw the plywood down and then use a levelling mortar to fill the trough, or I could place shims on the top of the 2x10 joist so that the plywood would lay flat.What would be a good material to use as a shim? or how would an expert proceed? Brent Thanks

[Nate Nagel]

can you use something like a red-i-post temporarily on the first floor to jack the joist up and then sister it and cripple it to reinforce? I would think that crippling at a minimum would be advisable if you're going to reinstall a heavy chandelier. Also use a ceiling fan box to mount the chandelier and reinforce it well while you have the opportunity.

nate

[Ken]

Have you considered securing a 2 x 8 to the side of the sagging joist and using the now level joist to secure your flooring to? If the fact that the 16 inch on center would no longer exist for that joist could be tolerated, that might be an easy way to go.

[ransley]

You could straighten it by taking heavy 2" heavy angle iron, drill holes every foot, take 1/2" coarse thread lag bolts, pre drill the wood with maybe 1/4" drill and tighten them down over a few days. it hopefully wont crack but sister another piece along side. If the hight is to high with the angle iron plane the beam a bit.

[S. Barker]

Fasten (straight) one by material (1x6 perhaps) to both sides of the joist in a fashion that makes it level.

s

[EXT]

Don't think the chandelier caused the joist to sag, some upon drying do tend to crown extremely, sometime down as you have, and as one in my house did, it went up creating a hump in the floor.

If the ceiling is drywall, you would be better to remove a 4 foot strip along the joist so that you can examine the whole joist. A plumber at some time may have hacked away all the strength when he was working in the area, at least you can then see what perforations there are in the joist. I would not leave it as it is as you will notice it from below every time you walk by. Fix it by sistering another joist, maybe one size smaller on each side if vertical clearance is a problem and cutting the old joist to push it up. Only by opening up the ceiling can you know what you can fit in there, and what pipes are in the way and may need moving either permanently or temporarily. While reno-ing the bathroom this is the time to fix it all.

This happens to me all the time, a relatively simple job snowballs into a major change in multiple areas.

[amyrbaker]

I think you would get best results from Ken's approach. Attaching a straight joist of the longest possible length to the existing joist would provide enough extra strength to support the chandelier as well as provide a solid level surface for the sub floor.

The sagging joist is probably the result of 'creep' resulting from the unplanned for weight of the light. Deforming the sagging joist without cracking it would take a period of weeks at least.

T

[Oren]

You are serious. I figgered this was a carpentry job ?!

Oren

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[trader4]

Am I the only one wondering what the ceiling below looks like? If the one joist sagged by an inch, one would think the ceiling below would be an obvious mess. And it wasn't caused by the chandelier below, at least assuming it's of the weight class found in typical residence applications.

Before I went with some type of sistering solution, I'd make sure the ceiling below is OK. You don't want to sister it only to find out that the ceiling has an obvious sag spot too.

[Oren]

Westheimer's Rule

To estimate the time it takes to do a task: estimate the time you think it should take, multiply by two and change the unit of measure to the next highest unit. Thus, we allocate two days for a one hour task.

:)

Oren

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[ransley]

Oren Ive seen it done on Roof overhangs that bowed, its easy. it raises the lower ceiling,

[marson]

Get a 2x2 of appropriate length. Screw down on the bowed joist with

3" construction screws. Snap a chalk line on the side of the 2x2 that is in plane with the rest of the joists. Unscrew the 2x2 and rip along the chalk line with a skilsaw. Glue and screw it to the top of the offending joist.

[trexxxmeister]

Thanks for all of the suggestions.I think I am going to bolt a 2x8 to the side of the existing joist and lay my subfloor on that.The house is 30 years old and I think a chandalier pulling on the joist in one focused area just caused the joist to warp over time.The ceiling below is a white and has a popcorn finish and unless you are looking very hard you dont notice a sag.I never noticed the old floor sagging or moving--I guess the old subfloor just bridged across the gap.