Framing a I-Joist Subfloor For a NEW HOME (DIY Guide)

Learn how to frame a I-Joist subfloor for a new home in this step-by-step DIY guide. Follow along as we show you how to construct a subfloor using I-Joists and install 3/4 T&G Flooring for a squeak-free floor. Whether you're a beginner or experienced builder, this complete tutorial will help you achieve a sturdy and reliable subfloor for your new home. Watch now and start framing your subfloor with confidence!

[@aristotle56]

Good work! I used I-joists for the second floor of a 2 story garage but used shop made squash blocks between the I-joists as I was concerned about snow load on the roof bearing down. More work but the spacing was really easy.

[@slothconstruction]

Thanks! More work but a good idea you had

[@bluesfool1]

Looking great! Can’t wait to see the next video!!

[@slothconstruction]

Thank you!

[@judithakerley3553]

Fantastic work! Love the hummingbird nest

[@slothconstruction]

Thanks! I will do little video updates of the nest

[@johnpearce3011]

Don't forget to add went wholes with screen for crawl space, you don't want to trap moisture in crawl space to cause dry rot.

[@slothconstruction]

Yes, for sure!

[@brandonbeaty6617]

Vented crawlspaces actually don’t work very well. If you go inside one, they are always damp and musty. Airflow through the little foundation vents is very minimal. Additionally- in the south what little air does come through the vents is very humid- that humid air hits the cool crawl space… and the moisture condensates on everything, leading to mold and rot over time. It’s much better to fully seal your foundation, put a vapor barrier across the walls and floor, to keep out the moisture, and run a dehumidifier. Additionally, you can insulate the foundation walls instead of the floor, adding the crawlspace/basement to the conditioned envelope of the house- this is by far the most energy efficient method, and leads to nice clean and dry crawlspaces. No mold or rot issues to deal with down the road.

[@slothconstruction]

@brandonbeaty6617 totally agree with you, I think if possible the crawlspace should be conditioned with the rest of the house. In this house we didn't do that and went with vents because it is such a dry climate here as long as the space is vented there won't be any issues with mold or smells. That's how the houses are built in this area and it seems to work well

[@johnnynephrite6147]

No earthquakes I take it. New Mexico?

[@slothconstruction]

@johnnynephrite6147 nope no earthquakes around here. This is in Southern Colorado

[@jst44216]

Do you need a I joist (BCI) on the ends or does the rim board osb efficient enough to hold up the outside walls where there is no BCI?

[@slothconstruction]

@jst44216 on the sides the rim board will support the weight, but in my case I had to add a second rim board since the outside one was bearing down on the icf not directly to the concrete

[@jst44216]

@@slothconstruction thank you for the reply. That'll help me build mine start next week or so. I planned on getting 2 extra bci that are 57' and 31' now that I know you can use the rim board I'll go with that to save money!

[@hammertime7349]

What’s with all the rocks. Where are you building this house?

[@slothconstruction]

There is a little dirt mixed in here and there. This is in the Rocky Mountains and the house site is near a creek so we have a lot of rocks. But go down the road 1 minute and it's all sand

[@EvgeniyaGuliuk]

Молодець❤❤❤

[@slothconstruction]

Thanks

[@iselagomez1036]

What size is the foundation perimeter?

[@slothconstruction]

It is about 32x32 with some inside corners so it brings it to a 132' perimeter

[@schlz69]

4X4 posts, what material is that? looks kinda red, and does not look pressure treated. if its not treated and in contact with the concrete, it will rot out in a few years.

[@slothconstruction]

Center supports are 6x6 and pressure treated. In this area the red pressure treated is what the lumber yards stock, I think I can special order a brown or green, but it is a ground contact pressure treated wood so we shouldn't have any rot issues.

[@schlz69]

@@slothconstruction great!!! I guess I havent seen read treating before, Different material in different places.

[@schlz69]

HUGE PROBLEM! with your rim board!!! Because your mud sill overhangs your foam, you need additional rim board that sits on the foundation on the parallel runs, otherwise the wall is not transferring load directly onto the foundation, you are bearing on the unsupported 2X8. Tis is in the IRC and applies in most jurisdictions in North America and most of the world.

[@slothconstruction]

Thanks for watching and noticing the problem. I got an email after posting the video about the same thing and we went back into the crawlspace and added a second rim board on the parallel runs so the weight would transfer to the center of the foundation wall instead of the edge. Next time doing a foundation like this I plan to point that out and add a second rim board.

[@schlz69]

@@slothconstruction What did you think of ICF? im thinking of doing a split level next year as a rental house, and use ICF for 4 feet basement, and wood frame the rest of the lower level. We have 2 basements going in this week for builds we are starting, a spec and one for us to live in.

[@jst44216]

Couldnt you just place another I-Joist (BCI) on the inside of rim board on the parallel runs?

[@jst44216]

I'm not a framer just an electrician and that's what I usually see when I'm roping houses

[@schlz69]

@@jst44216 Keep in mind, the rim is the load carrying member, I joists while structural, are not intended to catty the whole houses weight. Some designs do spec I joists as Rim, but the load calcs have been dome and they are within the weight carrying capacities. for example a Roseburg 400 series I joist is rated for 40 Pounds per Square foot, thats not much considering the cords are only 2.08" wide.