Lintel - did I fit it right?

[Lobster]

I had a fun DIY day yesterday putting a doorway in a loadbearing wall (first time I've ever tackled this). Before I remove the Acro prop I'd just like some reassurance that what I've done is OK! I'm not sure my method was exactly kosher, but I think the result should be alright.

The wall is a 4" internal brick wall; I supported it using a Strongboy/Acro prop while fitting the lintel (a Catnic box-section h/d one). I took out two courses of bricks, which meant there was almost

2" of vertical space to fill. The doorway is 27", and the lintel is supported by 8" at either end. I pushed the lintel up against the lower surface of the bricks above, and packed up the supporting piers with slates, before realising this really wasn't going to work effectively due to point loading. I carefully removed and repositioned the Strongboy prop underneath the lintel and cranked it up to take the load, then removed the slate packing. I replaced the slate with a fairly dry, 1:1 cement:sharp sand mix, ramming it into the gap with a lump of wood; and used the same mix (or slates where more appropriate) to fill any small gaps I could see above the lintel.

Now, next morning, it all looks very firm and rigid, but I was going to leave the prop in place for a couple of days to be sure it's set fully. The BCO will be inspecting it in due course, but before he comes round, does it sound OK?

I think I should probably have set the lintel up so the main gap to be packed was above it; is that right? If so, how do you avoid point loading on the two piers? In my case, the top surfaces of the piers were pretty old brick, and certainly couldn't be made perfectly flat. Also, the lintel is now slightly off horizontal, does that matter?; but it does faithfully reflect the level of the bottom of the course of bricks immediately above it.

Thanks David

[Toby]

Sounds fairly OK, my suggestion next time is to knock out one central brick above the lintel so that the strongboy does not interfere or need to be moved, put a bed of mortar on the lintel then use a car jack on a lower course to lift it in place, then pack bearing ends with slate/mortar as appropriate. Leave 2 days then remove prop & knock out doorway. Acro has well greased thread, so I'll wrap a bin bag to keep the dust off, and grease off if you see what I mean.

I mix with sharp sand but more like 3:1 and a bit soggier on top before jacking it up, never seems quite horizontal, but neither are the brick courses. Both have fitted within a single brick course. Personally I would not like to see > 3 pieces of slate stacked up. I guess a lot depends on the bricks used, old 1900 rough handmades have more curves than flats.

[Michael Mcneil]

The load bearing lintle should be horizontal to spread the weight evenly. I don't think it is that important that you follow the course above so much as the corses are fully supported and the way to do that is with a mix of packing and mortar. It's never going to be perfect, a little settling will occur so no real worries.

What is most important is that the wall is plumb and that the load is carried on half of a full brick each end. The load then spreads down evenly 45 degrees down and outwards. I don't see how you can jack the lintel up the way described with a car jack. Not and place it on the supports.

[Toby]

If you experience settling, then is the brickwork adequately supported?

Stick the jack under the lintel, then crank it up tight so that you can really ram the packing in under the bearing ends.

it for each end separately on the one in the higher load wall. If you have lime mortar it is wise to leave the plaster intact to help stop any wayward bricks dropping out.

You are right about positioning the lintel and opening so that the bearing surfaces are full bricks, although it can be annoying to have a doorway 2" from where you preferred it.

[Z]

In article , Lobster writes

What load will the acro jacks lift?

Are they available in small heights? I need to do some work under the floor

[Lobster]

[G&M]

Acros and car jacks have roughly similar ratings - 1-1/2 to 3 ton.

[Michael Mcneil]

Use a longer lintle.

[Z]

In article , G&M writes

Thank you, its a good fifteen to twenty years since I've used acro jacks (for propping up lift counterweights).