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Questions tagged [joists]

Horizontal support structures beneath the floor running between load bearing walls.

These may be solid wood, such as a 2x8, an engineered wood product, or a specially designed wood assembly with openings to allow the passage of utility lines through the joists (such as HVAC and plumbing) without damaging the structure.

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How to reinforce a joist with plumbing running through it?

After removing the sub floor in my bathroom in order to extend the sewer pipe for the toilet (it's too close to the tank-side wall), I found that the floor joists have extremely large holes cut in them to make way for the plumbing. What are my…
Jordan
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What are the guidelines for holes in joists?

I've been unable to find a good reference for the size/amount/location of holes I can drill through joists. This is mostly in order to pass cabling or pipes through the joist crosswise. Also, what about notching the bottom, is there a size…
Aaron
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Is it safe to remove the bottom chords of a series of garage roof trusses?

See attached picture. Looks like an 8x10 cut-out. He wants to lift cars up so he can walk under them. Is this safe? Doesn't removing the joists affect structural integrity?
Lynn Baker
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Is notching a flange on an I-Joist ever acceptable?

My home builder said that the following notch in a flange on an I-Joist was acceptable, but I've read that you're never supposed to do so. Is that true?
gibbo
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Contractor cut joist hangers to make them fit

(edited with additional info re. header) We are removing a couple of load bearing walls as part of renos in our home. The engineer specified a W8x21steel beam to replace the load bearing wall. The floor joists are 2x10. It appears the contractor…
user105375
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How do I meet the 7 feet high ceiling requirement after finishing the basement?

My basement ceiling joists are exactly 7 feet above the concrete slab. The requirement for finished living space is 7 ft from the finished floor to the finished ceiling. Since I'll loose a couple of inches with the flooring (I'll have Delta-FL…
Peter Q
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Is there a limit to the number of holes bored in a joist?

I already know that a hole bored in a sawn lumber joist cannot be within 2" of any edge or any other notch or hole. And that the hole can only be a maximum of 1/3 the depth of the member (International Residential Code 2012 R502.8). Given all this,…
Tester101
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How do I get to the wall cavity above a double floor joist from below?

I am running some new romex for a couple of electrical outlets. One of the outlets is on one side of a wall in one bedroom and the other outlet is on the other side of the wall in another bedroom. When I went in my crawl space to see what was below…
Ryan
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Is joist sag at connection with header a problem?

I am having the ceiling in the finished part of my basement redone, and have it fully open now. I can see the connection of the joists to the headers have given somewhat, as the house is 85 years old and the joists are not in hangers. The…
Paul D
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I want to build an all metal, self-designed building. Are metal frame and joists really that infeasible?

I have been putting together plans for my dream house. First an architect friend of mine said she might help, but right now she's got too much business and she hasn't even had time to look at a drawing. Then lumber prices were sky high and someone…
BSD
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Are there any dangers to sistering a joist with oversize lumber?

I've done some research lately on joist sistering as a solution to bouncy floors. The logic seems to revolve around the following principles. The stress of carrying a load is at the center of the span Taller is better than wider for a joist, i.e.…
Steve French
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Do I need a nailing edge around the perimeter of my room for my new AdvanTech subfloor?

I have torn out the original flooring from by 1910 Victorian so that I can level the joists and install new sound subfloor. I'm using 3/4" AdvanTech T&G subfloor, glued and screwed to the new sisters. What I'd like to know is if I need to install…
Doug Hill
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What is this orange yellow substance on my wooden studs inside walls?

There's some kind of orange yellowish looking substance that forms into tiny bubbles (it looks sticky, but I haven't touched it). It seems to be on my floor joists and wall studs. The house is from the 1960s. Is this something to worry about?…
DMR
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Structurally required? I-beam support under stair opening header

The stair opening into my basement is framed like this: A partition wall (non-load bearing) sits on top of the header. A square duct runs parallel to the header, and on the other side of this duct is an I-beam (3" x 3") supported in the center by a…
jmvincent
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Floor joists connection to eaves

Apologies if this is a duplicate. I'm attempting to floor my loft space. It currently has 47mm x 75mm ceiling joists, not enough for a floor. I am going to add something like 47mm x 200mm along side each existing ceiling joist, resting on the…
Adam Houldsworth
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