Walls – use engineered I joists as studs in a wall


Project: 3m by 6m weekend house, roof 3m high, walls 20cm insulation.

Question: I want build it from lighter/thinner materials, and i want to calculate from how thick materials i can build this I Joist (Picture One) So it would be same strength as 200mm by 50mm
timber stud.
I Joist will be 3m high.

Is there way to calculate thickness of materials for OSB and four Timber studs and how much load it can handle.


Picture 2

Best Answer

This is a bad idea to try and build your own I joists. Often the building codes will defer to the manufacturers specifications for engineered materials like I joists, engineered beams and also engineered OSB board. This is done because every manufacturer is different and because these manufacturers generally have actual accredited engineers that are certified and vetted who test these things in a methodical and proper way.

A small shed, on a residential property, is still considered a seperate structure, and as such is subject to your municipalities building codes, zoning requirements, by-laws and building permits. A review of your plan or an inspection likely will not pass and code enforcement may require you to tear down the structure if they feel it is unsafe. Inability to comply with code enforcement can result in loss of your occupancy permit for the residence.

Code aside, I think even using engineered I joists for studs wouldn't be the best idea. While I joists are okay for hanging drywall on a ceiling, a wall tends to have a lot more nails, screws and anchors run into it for everything from pictures, TV's hanging on lags, etc... With drywall, the screws will be run into the sides of the I joist where they will not damage the OSB in the middle. Running a nail or screw into the middle of an I joist greatly damages the integrity of the joist, and there would always be the possibility that somebody would attempt this and damage the stud. For a shed I am thinking about possibly trying to hang pegboard on the wall as an example.

Furthermore I can't even imagine how one can safely frame for a window or door with I joists. What is the proper way to nail the jack and king stud together? What if the wall is load bearing? Engineered I joists are tested when they are laid out on a span, not supporting load vertically.

Just use dimensional lumber, or purchase pre fabricated engineered I joists for supporting the load on a floor per the manufacturers specifications.