Support roof over door opening

[geraldthehamster]

I am building the outbuilding pictured, in my garden. It's 4.8 x 3.2. It will have a 24 degree cut roof with the ridge running lengthways, with clay tiles.

Can anyone suggest what size and material lintel I could put over the 2.6 door opening, to support the roof at that point? Around 4 rafters will land on it. I want to keep it as low as possible. I am assuming that a 65x100 concrete lintel with one steel rod in it will not cut it. Steel or timber? Timber fixed above the door frame would also gain the 50mm of the door frame as part of its depth.

All suggestions gratefully received.

P5260002

• geraldthehamster
• 26 May 2019

 

[^woody^]

You didn't guage down from the top of the frame then?

Anyway, two 6 or 7 x4's, and the rafters on hangers or a ledger to reduce the height by whatever the rafter depth is.

 

[geraldthehamster]

Thanks.

There's still a course or two of bricks to go on, front and rear, to give a level wall plate.

"Gauge"

 

[geraldthehamster]

Any way to get the height down from what you've suggested? Using 4x2s and screwing and glueing to the door frame gives a total depth of 6", but I guess that's insufficient.

 

[tony1851]

What's the depth, front-to-back?

 

[^woody^]

to give a level wall plate.

Do away with the plate at the front, and have a double beam like I suggested previously. This won't increase height.

No, 4x2 and the frame won't do.

 

[John D v2.0]

I'm no SE but you could always trim across it slightly higher up and do some doubling or tripling of rafters either side. Then you could lose the thickness where it's less critical for the door! Are you short on height due to minimum pitch and permitted development limits?

 

[geraldthehamster]

What's the depth, front-to-back?

3.2m

 

[geraldthehamster]

I'm no SE but you could always trim across it slightly higher up and do some doubling or tripling of rafters either side.

That's food for thought, thanks.

 

[tony1851]

if depth of beam is critical, a piece of 100 x 100 angle, with a 4" x 2" timber coach-screwed to the upright face from the back would do.
(the timber would contribute little to the beam but would just provide a fixing for the rafters).

 

[noseall]

a piece of 100 x 100 angle

Are you sure? What's wrong with 152mm x 89mm all of a sudden.

 

[tony1851]

Are you sure? What's wrong with 152mm x 89mm all of a sudden.

Sooooo funny In an ideal world, maybe, but a 152 + 50mm wall plate would take up 8" depth; it would also be way over the top structurally. The Hamster wants as slim a beam as possible, and angle iron would be ideal.

 

[noseall]

angle iron would be ideal.

We did a rotten rafter-end/wall plate repair recently using a similar method. Awkward bu££er too. Nowhere to bear the iron in the room I was fixing so had to transfer the beam through into the next bedroom.

Iron1

• noseall
• 27 May 2019

Window tight against a party wall zero bearing....

Iron2

• noseall
• 27 May 2019

Next door bedroom with angle poking through behind the two coax cables...

Iron3

• noseall
• 27 May 2019

 

[Ian H]

Are you having gable ends on it?

You could put a big purlin somewhere between the wallplate and ridge to take a lot of the weight.

 

[geraldthehamster]

Are you having gable ends on it?

You could put a big purlin somewhere between the wallplate and ridge to take a lot of the weight.

Gable ends, yes. A purlin is also a possibility