More lintel advice

[gh69]

Okay I have the specs from the SE on lintels for my enlarged (1.6m) door opening.

He's given me a choice of CN5XA catnic or 2x c24 44x122 timbers bolted together.
Both options will need a wall plate on top for rafters to sit on.

Is either option the preferred choice easier to source, simpler to install, cover up, live with etc.

Cheers

 

[hotrod]

You may struggle getting your C24 unless you order in advance or source from a large timber merchant.

CN5XA is a std duty box so you will have no problem picking that (or another manufacturer's variant of, IG etc) up at the builders merchant. I would go with the box.

 

[gh69]

Right, I now have a 2.1m CN5XA in my possession.

The rafters will sit on this, or rather they will sit on a piece of wood, with an angled top surface to match the rafter slope, which will sit on the lintel.

What is the best method for attaching the wood to the top of the lintel?

 

[freddiemercurystwin]

I particularaly like the way you thanked hotrod for taking the time to respond to your original question.

 

[gh69]

Yes I should have but didnt, sorry Hotrod.

Thank you for taking the time to point out my overwhelming rudeness

 

[freddiemercurystwin]

Always a pleasure and I thank you for taking the time to thank me!

 

[noseall]

A wall plate is usually mortar bedded to the masonry and across any lintels.

The rafters are then birds-mouthed onto the plate. The plate is not sloped to suit the rafter pitch.

The plate is secured using holding-down straps, however not across openings.

If the entire wall plate span is being borne by a lintel (unusual unless we are talking about say a hipped dormer) then it may be a better choice to use timber as a lintel.

 

[gh69]

Cheers for useful reply.

It was the structural engineer who said to use a sloped wall plate on top of the lintel be it steel or wood
Currently there is no wall plate at all, the rafters are just bedded on mortar on top of the bricks. This wall is halfway along the rafters span. The new lintel is to raise and widen the current opening and there will be no bricks above the lintel.