Installing a lintel.

[Dave Plowman (News)]

I'm going to replace an existing window - about 600mm wide - with a 2000mm wide one, the existing opening being to one side of the new. The wall is Victorian solid brick. It's on the first floor and there's only about 12 courses of bricks above where the new lintel will go - and the top half or so of that recent work as a new parapet wall to a roof terrace. I've read:-

But do the supporting distances (600mm preferred, 900mm max) still apply to a wall with so little weight on it?

If so, is there a way of not running Acros down to the ground on the outside? The area is scaffolded - would this take the weight? Or could I use needles through the lower wall which will be removed for the new window as well as above where the lintel would go? Or is there something custom made for this I could hire?

Just as an aside I had the same job done to the floor below, and the builders didn't bother with any supports at all - simply smashed the hole through. They reckoned they'd done it hundreds of times without probs. But if I do that it will be the humndreds plus one - knowing my luck.

The other thing is the room the new window's going into is in pretty good condition so I need to minimise any internal damage.

[George]

Are you down to the brick in the room were the lintel is going?

I'd tackle this like so....

I'd take out the run of internal bricks were the lintel is going to go,shove the lintel in the hole as much of it will fit and support it internally for safety. Then take out the outside course of bricks and internall push the lintel to fit with the wall outside.

Job done.

[Dave Plowman (News)]

Yes.

Snag with that is it's a 'solid' brick wall - made up of headers and stretchers.

[Cicero]

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[Lobster]

If you use Strongboys as reccommended in the above, you only need Acrow on one side of the wall to be propped, which could be inside the house. Obviously you need to ensure the Acrow is standing on a firm base to spread its load; ie on joists not just floorboards.

David

[George]

Whats the acrow for and where does it go?

[Andy Burns]

If you read that link, it ought to be clear.

[mail]

=A0 London SW

Two acrows 'on edge' opposite either side on a header at about 1 m centres will be fine if you don't have tallboys.

If it is Victorian, it will most likley be lime plaster and that sticks better and is more flexible than cement. Just dont breathe too heavily as you put it in! (smile) Chris

[George]

I have read the lnk,but in Mrploughmans situation they're not needed as its only twelve courses of bricks above ie its not the ground floor area. The strongboys is all thats needed,if the builders can knock a hole out in the ground floor without any props and any structural damage? then what MrPloughman is attempting will be a doddle but he's getting too worried about it.

[Dave Plowman (News)]

It could be the fact that a building has just collapsed round here while they were excavating the cellar. ;-)

[Dave Plowman (News)]

What I'd really like is a sort of double ended Strongboy - remove a couple of bricks from where the sill will be and support above where the lintel will go off that. All from the outside. Does that sound feasible? It's rather a long way to go down to the ground - and I'd have trouble transporting Acros that big. And lifting them. ;-)

[dennis]

If you knock out a brick below the lintel and put a 2x4 through and then do the same above and then wedge a 4x2 vertically between them either side it should transfer the weight and enable you to remove the bricks between. It should do it with ease if there are only 8 courses to support, however do make sure its not supporting the roof as well.

You need one every few bricks BTW.

[Dave Plowman (News)]

I've been down the hire shop and got 4 strongboys and two short acros. I'd not seen strongboys before and was worried they could tilt if anything moved - but they support themselves on the acro to prevent this so I think I'll be ok.

No - the roof terrace joists go from side to side, and the window is in the end wall.

Sorry to be such a wimp about this ;-)

[Rob]

Coming from a place of near complete ignorance, why not use two cheap bottle jacks?

Rob

[sm_jamieson]

What is the amount of force you should usually put on the brickwork when supporting it on acrows (screw-turn) or indeed a bottlejack ? Presumably just a little more than just supporting it. Simon.

[Dave Plowman (News)]

Bottle jacks don't usually have the height needed. The smallest acros go from about 1 metre. Larger ones go floor to ceiling. They have a screw thread which gives about a foot of adjustment, and a hole and peg system for larger coarser adjustment - like a car axle stand. But you don't use a an acro to jack something up really - just get it solid before letting a load settle on it.