Can a timber beam be used instead of steal I beam RSJ?
Anonymous user 23/02/2024 - 3.31 PM
Hi folks, I’m currently building a granny annex at the end of my garden, built from concrete blocks with a 100mm cavity. measuring at 7.2m deep, 5.2m wide and 2.5m high with a flat roof
Iv been toying with the idea of bolting two roof rafters together to make a beam to hang the roof rafters from, instead of using a steel I beam RSJ. As I believe this will be more cost effective in materials and labour.
(Beam width approximately 4.8m)
I just wanted to know if this is a good idea or not? And if so what size timber would be most suitable?
Would appreciate any suggestions many thanks
Are you a tradesperson and able to answer this question?
Not a good idea... if it’s a granny annex then it’s being built to live in/sleep in.. therefore it needs full building regulations for footings, structure, insulation etc and planning permission and you will need structural engineers calculations for the steels... absolutely no question about it... hope this helps
You can use timber , min 200x50x2 but you will have to make it a flitch beam .
This means a 10mm piece of steel in between the two timbers bolted through each other. Steel must be same size as timbers .
It’s another way of doing it but H beam quicker
Answered15 May 2020
0
Anonymous user
We've recently completed a new build where originally steels were factored in on the design by the architect to support the upper floors.
Our structural engineer decided to use two Glu-lam beams. In short engineered wood bolted together which was abit cheaper, but mainly it was a lot lighter which made the job certainly easier for our backs.
I would strongly advise getting a qualified structural engineer to look at the design and drawings if there are some. He can look at the loadings and advise what is best suited for your project.
