Hi I am removing a brick support wall from the front centre of my garage so that we can put a single garage door on instead of two seperate ones. As I haven't gotten into the roof as yet I am not sure what size the beam is, I was talking to a builder friend of mine and he said that if the beam is one piece and not joined above that brick pole and is a minimum of 120mm thick then we can take out the bricks without any further bracing. However I talked to another builder friend and he said that it would need to be 200mm. Once the pole is out the beam will be spanning over a 6m distance and the roof is tin, so there isn't alot of weight in it. What I was wondering is does anyone know what the minimum thickness the support beam needs to be to span that 6m distance?
Roughly translated 120mm is 4 3/4 ins, 200mm 8 ins and 6 metres is 19ft 8ins.
Timber isn't my chosen subject, but 120mm for 6 metres seems a bit weedy. It also depends on the type and grade of timber, and also imposed loading such as snow.
It would not be safe to make the assumption that the removal of the brick between the garage doors would leave the header structurally sound. In most circumstances, a new header of sufficient size to carry the imposed loads will need to be installed to span the entire opening.
You'll need engineering support to size that beam for you.