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

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24
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1answer
57k views

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 ...
14
votes
3answers
2k views

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?
12
votes
3answers
16k views

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 ...
10
votes
1answer
1k views

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 ...
9
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2answers
3k views

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 ...
9
votes
1answer
1k views

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. ...
8
votes
4answers
3k views

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 ...
7
votes
6answers
3k views

How do I remove floorboard nails from joists?

How do I remove floorboard nails from joists? The nails are ~3-4mm diameter with no heads. I've tried claw-hammer and wrecking bar with no success because without nail-heads, I cannot get purchase. ...
7
votes
2answers
20k views

What size ceiling joists and rafters should I use for a 14' span?

I'm going to build a single story addition to my home with a width of 14ft. I plan on using ceiling joists every 16" but I'm not sure which size to get. The roof will be asphalt shingles and the attic ...
7
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2answers
1k views

How do I measure joist deflection?

I have a 3 story townhouse that was built in 2004. We recently redid the flooring in the top floor, and while we had the subfloor exposed we tried to eliminate the squeaking that we've been hearing by ...
6
votes
2answers
152 views

How to improve wooden joists without removing them

First floor bathroom in a Victorian terrace house. Floor joists run left to right with floorboards laid front to back. Joists are approx 10 foot long. At some point in the past, the previous owner ...
6
votes
1answer
273 views

Is a toilet drain permitted to run through I Joists?

It was suggested by a plumber, but is it common practice? The I joists are 11 7/8" but a 3.5 or 4" toilet drain line seems like a large hole to be cutting even if it's in the middle of the joist's ...
6
votes
1answer
54k views

How do I determine if a wall is load bearing?

I'm considering removing a wall in my master bathroom but I can't tell if it is a load bearing wall or not. I've done a fair amount of research. I don't have the house blueprints, and it's difficult ...
6
votes
1answer
2k views

Should I worry about sagging joists?

I have a two story house and some of the joists between the floors are sagging about an inch or two. When I walk around upstairs I can feel the level difference and downstairs you can slightly see the ...
6
votes
1answer
21k views

How can I attach a ledger board to my house?

Spring is here so I finally started to take measurements for materials I will need to build a new deck on my recently constructed home. I just realized that this isn't going to be quite so simple as I ...
6
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2answers
5k views

What should I do about a hardwood floor that's sagging between the joists?

I recent bought an older (1890) house. On the original floors, the wood flooring is sagging between the joists--you can feel the height difference as you walk, up and down, up and down. It's firm, it'...
6
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1answer
851 views

How do I fit a joist in this small space?

This is a follow on question from here: Floor joists connection to eaves Since this question, I have been told I need 8" joists for my span and I have exposed my eaves area to see what space I've ...
6
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1answer
852 views

How to properly seal the transition between basement wall framing and spray-foamed box joists?

We're looking at insulating the box joists of our concrete foundation. We have 2x3" walls framed which are holding batt insulation, which are 3-4" away from the wall (to accommodate a layer of batt ...
5
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3answers
2k views

Is it OK to drill vertically through a joist?

I just bought a new house and I'm looking to run some cables. One of the areas I would like to run it to would require drilling through a 2x10 sistered joist. Realizing that going through the joist ...
5
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4answers
133 views

How to install 2x10 joists of slightly different sizes?

We are trying to install the joist hangers and the joists, but the 2x10s are slightly different sizes. The problem is that some of the boards are 9.25" and some are 9.5" and some in between. So if all ...
5
votes
2answers
449 views

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 (...
5
votes
1answer
3k views

Is there a correct orientation for hurricane clips?

When installing hurricane clips to joists where it crosses a beam, is there a preference to mounting the clips on the inside or the outside of the beam? And should the ears on the clips point inward ...
5
votes
4answers
3k views

How do I repair a floor joist which has a hole drilled less than 2 inches from the bottom?

I have three floor joists that have approximately 1/2 inch hole in them less than 2 inches from the bottom. Is there a recommended fix or approved method to correct this to meet code? These joists ...
5
votes
4answers
3k views

How do I deal with a joist in the way of where I need to run a pipe?

I'm in the process of installing central vac lines (2" OD) in a finished house, and I am trying to run a line into the upstairs hallway. I have removed drywall in the garage below and drilled a hole ...
5
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2answers
4k views

What should I do about this load bearing wall that is only supported by a joist floor?

My floors pitch in the same spots as they do on the 1st and 2nd floors. My home was built in the 1890's. I have some soft spots in the basement joists and added 4x4" posts to each side of the main ...
5
votes
2answers
310 views

Free-standing deck joist layout

I'm trying to plan out a free-standing deck in an irregular-shaped garden. It currently has railway sleepers marking a garden bed around the west, north and east edges and the missus would like to ...
5
votes
5answers
2k views

How to support the subfloor around a toilet between I joists

I'm replacing some rotted subfloor around a toilet, and I want to add blocking around the flange for extra support, and to give me a place to support the new pieces of subfloor (I'm not planning on ...
4
votes
2answers
1k views

Should I add plywood or OSB between sistered beams?

I'm going to stiffen up my main floor joists by sistering then bridging them. In the past a friend put something in the middle, is that standard? Should I put 1/2" plywood or OSB in between?
4
votes
2answers
584 views

How do I reinforce the ends of 2x8s that are sistered to 2“x5” (actual size) joists?

I want to strengthen the floor of my office. Currently the joists are 2"x5" (actual size). I want to put a 2"x8" (1.5"x7.5" actual size) which will double the existing joists. I will have to reduce ...
4
votes
1answer
2k views

Do the guidelines for holes in joists apply to band joists?

This question have a great answer with all the guidelines for drilling holes in joists. The question: Are the guidelines the same for band joists? A bit of context: I'd like to add an exterior ...
4
votes
1answer
4k views

What does blocking refer to in relation to floor joists?

This question was triggered by the following line in a home inspection: Blocking is not installed for I joists above beams in basement. I have found pictures of blocking at http://www....
3
votes
1answer
5k views

How can I remove just one tongue-and-groove subfloor board?

I am not talking about laminate planks, but actual subfloor sections. My entire room consists of tongue-and-groove boards. I was under the impression that the point of this was so you didn't have to ...
3
votes
2answers
3k views

How can I hang a heavy bag from this beam in my garage?

I'm renting a house that was built about 10 years ago. The attached, finished garage is under the master bedroom. It has two large beams running across it, see picture. The larger one is 6.5" ...
3
votes
1answer
170 views

Why does the maximum deck overhang sometimes decrease with joist spacing?

The deck construction guide for my area contains this table: Look at the "Allowable Overhang" columns. It's odd that a wider joint spacing (24") permits a longer overhang. For example, look at ...
3
votes
1answer
237 views

Where in the span of a floor joist can I drill holes to run wiring?

How far from the end of a 2x12 or 2x10 floor joist can I drill a hole? NEC 502.8 does not give this answer, only that you have to be 2" above or below the edges, not in what part of the span it has ...
3
votes
3answers
229 views

Joists have different height

I'm first time homeowner and bought a house (built in 1999) in fall of 2015 (Philadelphia suburb). During inspection of the house I noticed squeaky floors and inspector said its due to nails rubbing ...
3
votes
1answer
483 views

What materials and spacing should I use for ceiling joists/strapping in this conversion?

I have an old two bay garage that's 28'x50', that I would like to convert into a home. One thing I'm trying to figure out is how to do the ceiling. The ceiling is held up by metal joists approximately ...
3
votes
2answers
84 views

What to use as a spacer where deck joists overlap?

I have a long deck that must do sister joists on top of a beam. I was reading this thread Is deck joist sistering a sloppy repair? and look like it's better to use spacer in between. Is it OK to use ...
3
votes
2answers
608 views

Is there a way to sound proof my basement while I've got part of the ceiling open?

We had a header beam installed in our basement. The floor joists are exposed for 1ft (~30cm) on both sides for the length of the beam. The basement is an apartment, so I'd like to add some sound-...
3
votes
1answer
2k views

How can I permanently fix a sagging floor?

I have a home I purchased roughly 18 months ago. The house is a traditional 2 story cape code (3BR 1BA) and is structurally very sound and extremely stable. However, on the primary floor of the house,...
3
votes
1answer
73 views

Help running ethernet between floors, with double joists in the way

I will like to redo the existing Ethernet (and maybe COAX) wiring in my home. I have looked for the most ideal path from the basement through the floors into the attic and then drop into the second ...
3
votes
0answers
60 views

How can I reduce the bounciness of a floor? [duplicate]

My apartment is on the second floor of a low-rise building. There are no units directly under it; the apartment sits above the open-air garage. I feel basically everything that my next door ...
2
votes
1answer
265 views

Hurricane ties installed using joist hanger nails top AND bottom. Should I yank them out?

I'm using double sided hurricane ties to secure my joists to my beams for a deck I am building. The tie looks like below: I had been using 1.5" joist hanger nails for the 6 holes at the top that ...
2
votes
2answers
131 views

Structural cross joists and load-bearing walls (century home)

I have a friend that recently took possession of a century home. Its a 4 plex and He was told it was an old school house (at least at some point in time). We’re experienced weekend warriors but ...
2
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2answers
2k views

Do I need to brace joists after removing basement ceiling?

I'm about to take out the lath & plaster ceiling in the basement of my 1908 house (I'm hiring it out; I know how bad the mess is). Main reasons for doing this are to get access to wiring and allow ...
2
votes
2answers
230 views

How to find joists through sheetmetal ceiling?

I have an antique sheetmetal ceiling of historical importance in my centenarian vintage home. As I am currently in the last stages of installing an AC system and the parts of the house that have ...
2
votes
1answer
54 views

I need help supporting and jacking up my attached, wood front porch

I live in Ohio in a home built in 1926. I do not believe the front porch is that old. The porch is L shape, wrapping around the house and is 24 X 8' in the front extending another 14' back, with ...
2
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2answers
25 views

ceiling joist storage expression

I have pre made truss ceiling joist in the garage. The joists are 2x4x21'. I want to use space above the joists for storage. I want to sister a 2x6x21' or 2x8x21' next to 2x4x21' is this ok? If ...
2
votes
1answer
67 views

Can I use the area above my garage for an extra room?

I want to use a 8 x 20 space above garage for an extra room (Load Bearing). It has two 2 x 10’s sister’d together spanning of 20 feet and 16 inches apart with no center support. Can I make this set ...
2
votes
2answers
3k views

What packing material to use between a brick and house beam?

I'm replacing a damaged beam under my house with bricks under each floor joist. The bricks are 15mm lower than the original beam. I've been told to use roof slates to pack the rest of the height. I'm ...