Advice on garage lintel

[thelandlord]

Hi,
Need some advice please.

Building my own garage and have put the lintel up today,it is a 14 ft opening and the lintel will be taking attic trusses with light weight fibre slate,should i put the trusses up first to load and settle the lintel before i put the face brick work on it and also it is a heavy duty one that has the blocks in the back of it,do i put the blocks in first then let it set for a week before putting the trusses up or load it first with the trusses?

Thanks for any advice.

Link to build
http://bbs.scoobynet.com/diy-39/568283-my-diy-garage-build.html

 

[^woody^]

I'm assuming it is a steel inverted 'T' shape lintel, and therefore the strength relies on 3 course of brick external and the course of block internal being built on it first.

You need to let the brick and blockwork go off for a few days before loading it.

Also make sure you prop it in the centre or it will sag and throw the bricks and blocks on it out of plumb.

 

[thelandlord]

Hi Woody,

Thanks for reply,this is the lintel http://www.igltd.co.uk/diagrams/diagram.php/LID=41

The face brick work does not help with support,the blocks in rear stop it sagging,if i prop it first wont it sag and crack the mortar when support has gone and trusses load it.

Also do i need to put some dpc and weep vents in over lintel.

Sorry if i sound a bit thick here as this is the first building work i have done and learning all the time.

Thanks for your time.

Paul

 

[^woody^]

Who specified that lintel?

You are using a cavity lintel, but only loading the internal leaf. This type of lintel is designed to perform with both internal and external leaf equally loaded.

These lintels work by the brick and blockwork forming part of the support - so the lintel is supported untill the first few courses have gone off, and then when you remove the support the lintel will not sag because the courses above are in compression.
If you don't support it, it will sag once the first few courses are laid on it, as the weight starts to compress the soft mortar before it has hardened. So it will then go off in that sagged position.

You are also point loading the lintel with trusses quite near to it - again something which these lintels are not normally designed for.

You should check with IG that this use is acceptable, or whether a different lintel is required.

You don't need a cavity tray and weep holes if the roof soffit is just above it

 

[thelandlord]

Hi woody.

The builders merchant said it was the one.

The build is a 50 mm cavity and the lintel will have face brickwork sat on the front,mayby 6 courses or so and 1 course of block in the back then the wall plate on that then the trusses.

Is this not right then as you have me a bit worried now.

Thanks Paul

 

[thelandlord]

Hi,

Just had a look on catnic and ig sites and this seems to be the right lintel,i will support it as you say and let it go off for a week before loading it.
The eaves will be right above it.

Is there a standard thickness for wall plate?

Thanks for help.

Paul

 

[diyisfree]

4" X 3" timber for the wall plate

 

[thelandlord]

Thanks,
i will do it this week end ready for the roof next week.

Paul