Which Lintel do we need for our garage windows?

[Sappy]

Hi all,
We are in the process of building a new garage and a brickie is going to face our block walls and build pillars and apex etc.. we have left three 500x900 gaps for Windows on the block wall immediately below the roof plate. There is to be no cavity as such between the block and brick wall. What lintels will we need over the Windows on the brick facing walls? Will this mean the Windows will have to be smaller so there is a course above the lintel to align with the roof plate on the block wall? Will the 4x2 wall plate be sufficient to support the roof load or should we have installed something for both walls? I have attached a pic of the build part done before it was ready for the roof plates etc..
thanks Lisa

 

[catnick67]

Catnic CN71

 

[Doggit]

How thick is the roof plate, and is the opening 900 wide, or 500 wide. If the latter, then I wouldn't bother with a lintel. Actually, I'm not sure I'd bother with one either way.

 

[Sappy]

Hi
The roof plate is 4" wide and 2" depth.
The Windows are to be 900mm wide and were to be 500mm deep but will now be less if a lintel is required.
Any advice gratefully received
Thanks Lisa

 

[Doggit]

What sort of windows are you putting in. You've a 4x2 roof plate that will have at least 1 truss sitting on an open space. If you're using double glazed windows, then they'll be strong enough, but wooden windows might be a bit suspect. If you want to play safe, just put a 1200mm concrete lintel over the opening before the roof plate goes on.

 

[Sappy]

We were going to put in double glazed windows, fortunately not ordered yet so sizing can be amended. Would a single skin L lintel be as effective or maybe a corrugated one? I guess the brickie would install whatever is best? Thanks

 

[Doggit]

An L lintels not appropriate, as you've only got 2" on the roof plate, a corrugated ones a bit of an overkill.

Talk to the double glazers, and see if the can put reinforcement in the frame.

 

[cjard]

Does the wallplate bear any roof load ? (I ask because I can think of situations where the roof supports are on the other walls

If you had your heart set on 900x500 windows, don't forget that if you do put a concrete lintel in you can always knock a course of brick out of the window sill level, and get your 500 back

Regards the people saying you might be able to get away with no lintel, I don't think it would have washed with my BCO - he made me fit a concrete one (wasn't allowed a catnic either) to a wall where there were 3x 400mm wide windows, with 440 wide pillars between, because the wall was carrying the roof trusses, even though I could space out the trusses so that they were bearing directly onto a wall rather than a window

 

[Sappy]

We've gone for 1200mm concrete lintels over the Windows as the trussses do sit on the wall plate which is sat on the block wall. I guess once the brick walls are in we can look at whether to amend the sizing of the opening or the Windows.
Hopefully the load will sit over the two skins equally. Thanks again