Changing Timber Lintel To Concrete

[DIY-AMATEUR]

You could dry-pack this gap.
3 x sharp sand, 1 x cement, mixed with just enough water to be able to form a ball when squeezed in your hand... not wet like mortar.
Ram this in the gap, and tamp as tight as possible. This will be acceptable to fill that gap.

This method is used in some underpinning.

Thanks for the reply. I had read about dry packing but didnt know if that would work at the 10mm end of the gap?

 

[Mr Chibs]

I've read it can be used safely up to 50mm. I recently used this method similar to what you want to do, 35mm tapering down to 15mm.
It dries rock solid!

If your sand is damp, mix without water, see if you can make a ball, if not, add a small amount, I wasted my first batch as it was too wet.

 

[DIY-AMATEUR]

I've read it can be used safely up to 50mm. I recently used this method similar to what you want to do, 35mm tapering down to 15mm.
It dries rock solid!

If your sand is damp, mix without water, see if you can make a ball, if not, add a small amount, I wasted my first batch as it was too wet.

Thanks for that. Just for clarification use sharp sand and not soft red builders sand?

 

[DIY-AMATEUR]

A builder nipped around last night to have a look at the lintel and he said if he were doing it that he would leave everything as is and just pack the 30mm tapering to 0mm gap all the way across with slate hammered in.

I would just like a second opinion on that please v's dry packing with sharp sand/cement?

My only concern with the slate is it might leave some voids that i cant see where as the dry pack being rammed in would make full contact with the lintel in the large gap. I doubt the dry pack would work on the side that tapers to 0mm though as i wouldnt be physically able to ram it in so the slate would probably work better there.

I wish i had the money to employ people to do these jobs to save over thinking every little thing. I just dont want any cracking to appear once plastered and put me back to where i started!

Cheers

 

[Mr Chibs]

Think I'd just dry pack... but if you felt happier, fill what you can with slate and dry pack the left over voids.
Sharp sand is preferred, have a search, folk have used builders, sharp, grit... blah, blah, blah.

Whatever method you use, you will be improving what's there... bodgers would just use expanding foam!

 

[DIY-AMATEUR]

Think I'd just dry pack... but if you felt happier, fill what you can with slate and dry pack the left over voids.
Sharp sand is preferred, have a search, folk have used builders, sharp, grit... blah, blah, blah.

Whatever method you use, you will be improving what's there... bodgers would just use expanding foam!

A combination it is then! Thanks mate.