Author Topic: I-joists (Read 3369 times)

fiddle1 · « **on:** May 30, 2011, 10:42:53 PM »

has anyone made i-joists at home?

i have this very old house im fixing-----the floor rests on a wood joist that has become badly
weathered. in order to make it proper i need to have an I- joist that
connects from a sill plate to a sill plate. (actually 4 of them to distribute the weight properly)

the problem---you guessed it-----

24 feet sill to sill......the older house was real long
---they could get timber that long
in 1920's no problem....

but today the best i can do is 18 ft long i-joists from a hardware store-----
its pressure treated wood routed to accept OSB
in a letter I- shape is best i can do.........

i checked into a steel I beam 24 foot in metal was almost $600.

if i got two of the i joists at $25 each could they be spliced together somehow to make the 24 foot length?
im still trying to figure out how to connect them without making a pivot point, or inviting ruin.

suggestions welcomed.

beenthere · « **Reply #1 on:** May 30, 2011, 11:03:14 PM »

24' without support posts?

What is the "floor" construction that rests on this I-joist?

I get the feeling you are talking of a king beam that floor joists set on, but maybe just not connecting here.

I-joists can be purchased up to 40' long, but may be expensive to get them (or one) delivered.

Here is a YouTube vid telling about I-joists

Bandmill Bandit · « **Reply #2 on:** May 30, 2011, 11:26:35 PM »

I have 24 foot I J's over my garage in my house. They are 22"deep(i think) and on 16 inch centres . I will measure and take a pic tomorrow.

thechknhwk · « **Reply #3 on:** May 31, 2011, 03:26:01 AM »

These "I" joists are the firefighter's enemy - not that you plan on having a fire, but the centers burn out quickly then they collapse easily.

Bandmill Bandit · « **Reply #4 on:** May 31, 2011, 10:15:18 AM »

Yes the OSB does burn pretty fast. In the last couple of years a spray on coating has been developed that is now required to be used on the IJs for fire protection around here. It is a pink colour and the demo I saw the stuff does not burn.

beenthere · « **Reply #5 on:** May 31, 2011, 11:47:06 AM »

Quote from: thechknhwk on May 31, 2011, 03:26:01 AM

These "I" joists are the firefighter's enemy - not that you plan on having a fire, but the centers burn out quickly then they collapse easily.

Normally not allowed by code to be exposed, but behind sheetrock (drywall).

We haven't heard much back from the OP fiddle1 as to what his plans are for I joists.

D Hagens · « **Reply #6 on:** May 31, 2011, 11:56:04 AM »

Are you looking for I-Beams, I-Joists or silent floor

I've dealt with all of these products and they all have an application that if followed right will last forever

Texas Ranger · « **Reply #7 on:** May 31, 2011, 04:55:38 PM »

Boise is a source for over length beams and such.

SwampDonkey · « **Reply #8 on:** May 31, 2011, 05:45:53 PM »

They used to make'm here about 20 miles away. They needed black spruce for the top/bottom and OSB they imported.

fiddle1 · « **Reply #9 on:** May 31, 2011, 10:07:16 PM »

sorry been busily climbing under the floor
trying to fix the plumbing.....

ive

been underneath it looking at the beam
again, it is supported by a floor jack in the middle, a wood peice resting on a sill
at the other and then they made a wall in the basement down the middle with concete
bricks, then filled the half of the basement with dirt to hold the
other end of the joist with two larger wood blocks. (it was really scary)

the end of the beam doesnt extend to the other concerete sill, but falls short of it.

my goal would be to support the upper floor on new joists (more of them instead of one big one)
and add newer floor jacks
remove the wall and get the wall and dirt sill out of the basement
to reclaim the floorspace.

i need to store snowblowers and such and a basement would really be useful.

fiddle1 · « **Reply #10 on:** May 31, 2011, 10:12:36 PM »

my goal is to take out the rotted wood in order to make the floor itself stable, with newer joists supported with newer floorjacks. my problem is longer length needed to do so -- 24 ft.

what other application would work to solve this?

Bandmill Bandit · « **Reply #11 on:** June 01, 2011, 12:15:03 AM »

Truss Joists. but the need more head room and they are more money.
Glue Lams would work too. not the real big ones but 1 7/8 to 8 X any place from 6 3/4 up to 32 depending on load and length. I have one that is that is 2 7/8 X 9 1/2 X 22 and it carrys the weight of the ceiling joist and rafters for half of a 28 by 62 foot bungalow where i took out a weight bearing wall when I renovated. They look like a piece of plywood but are long beams. longest I have seen is 72 feet. It was 8" x 32" x 72'.

just walked over a set of 32 footers this evening when I walked the dogs for a new house just a block away. I will get some pic if i can and post em tomorrow.

shelbycharger400 · « **Reply #12 on:** June 11, 2011, 11:01:56 PM »

my house here, 1960's, 24 ft wide x 38 ft long , they used 6x6 posts upright, they nailed 3pcs thick 2x6's together to make a load bearing beam down the middle. on top of that is 2x8'x12' stagered for my floor joists.

if you have 24 ft to span... sounds like id pick up 2, 12 footers, and a few 6 footers to make your own lam beam and nail them together with 3 in long nails . if you can put a post in the middle for support. go with a green treated post if it touches the concrete floor. have a few friends over, and built it as you go in place, it will get heavy fast !

ljmathias · « **Reply #13 on:** June 13, 2011, 04:32:30 PM »

Heavy and dangerous- we used a laminated post for about the same span for our house and it weighed in at a ton even; had to hire a crane just to put that up!

Also, you might want to put a piece of roofing felt or shingle under any post in contact with concrete- stops the moisture wicking which can cause even treated wood to rot.

Lj

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