New Garage Questions

[owenyboy]

I'm going to be building a new double garage soon. I'm not sure about a couple of things and would really appreciate some advice.

I want to have one double garage door rather than 2 singles. I'm not sure if it is possible as the width of the garage will be 5m and the width of most doors seems to be 4.3m. Does this leave enough room to support the lintel? I'm not sure what size the piers would need to be. Does it help if I build a cavity wall rather than single block walls? If it needs to be wider, how wide should it be?

Also, what type (and size) of lintel would be best? The roof will either be flat or a low pitched slate 'hip' type roof, so I don't expect it to need to support a lot of weight.

Thanks in advance.

 

[owenyboy]

I've read that a lintel would only need to sit 150mm on each side. Is this true even for a span of 4.3m? If so, would I get away with having this on a garage 5m wide? i.e. 350mm wall either side of the garage door?

Any suggestions/advice welcome.