Garden room lintel

[Montyman]

Hey everyone. I’m just designing the lintel arrangement for the front of a garden room building. The walls are being built using 4 x 2 studs on 400 mil centres. The roof rafters are 6 x 2s also on 400 mil centres, supporting 18mm tongue and groove OSB and 1.5mm EPDM covering. The span of the rafters is 3m.

On the lintel: I need to make a gap for French doors 1.4m wide, and separately to the side of the doors, for a casement window 700mm wide. Rather than have two separate lintels I was thinking of making one 2.8m long one, made of doubled up 7x2s, sitting on cheeks of 200mm width, with a suporting column (same construction as the check of 2 jack studs and a head plate) in between the door and the window gaps that is 250mm wide. The single lintel would then be sitting over one span of 1400mm and one of 700mm.

Questions:

1. Is doing this with one long lintel supported by a column in this way more structurally sound than having two separate lintels?

2. Are those 200mm cheeks sufficient?

3. Are the 7 x 2 is sufficient for the size the 1.4 m span, or the 2.4 m span if that is still relevant.

I’m a little nervous on this one! Thanks.

Tom

 

[23vc]

picture might help, but trying to visualise why you wouldn’t just span the whole thing anyway, and have that as part of the wall top plate. But in any case 7x2 (for the 1.4m span, anything else is kinda irrelevant) is very much more than ok. Might be too deep though depending on your ceiling height needs and aesthetics. I’d be looking at just running doubled up 4x2s across the whole wall with openings formed below for windows and doors.

 

[tony1851]

1. Yes

2. Yes

3. Yes, but as per 23vc a bit over the top. A continuous beam is generally better than two separate beams.

 

[Montyman]

 

[Montyman]

1. Yes

2. Yes

3. Yes, but as per 23vc a bit over the top. A continuous beam is generally better than two separate beams.

Thanks guys. Photo attached of the plan showing 7x2s. Sounds like if I replace that with doubled 6x2s it should still be fine. Is that right? That was my original plan but then I saw lots of folk on YouTube using double 8x2s or steel beams for openings of only about 2m, which gave me the fear.

BTW, two details. I have the cheeks attaching to doubled king studs at the end of the wall, to give me a way of attaching the end studs of the side walls. Should if you see a more elegant way of doing this.

And last, you’ll see my middle column as one jack stud on the left and 2 on the right to support the longer span of the door. I’m now thinking this is maybe overkill as well…. Agree?

 

[23vc]

The chunkier lintels in garden rooms tend to be for top hung heavy bifold doors, which would have a span much wider than yours and would need to carry the weight of the doors, rather than just the support of the roof above the doors, which may be why there’s talk of steels/8x2s on YouTube.

Full height studs doubled up at each end pretty normal, dont really need the double to the left of the door, but not really a biggie, more studs = slightly more cold bridging…

 

[Montyman]

The chunkier lintels in garden rooms tend to be for top hung heavy bifold doors, which would have a span much wider than yours and would need to carry the weight of the doors, rather than just the support of the roof above the doors, which may be why there’s talk of steels/8x2s on YouTube.

Full height studs doubled up at each end pretty normal, dont really need the double to the left of the door, but not really a biggie, more studs = slightly more cold bridging…

Thanks 23vc. I will remove that extra stud within the supporting column on the left of the door to allow more insulation and, as you say, to reduce the bridging.