House settlement repairs - fixing cracked lintels

[l.c1]

Hi,

I am getting a bit doubtful about doing this myself but I thought I'd see if there is anyone who has !

I live in an 1870's property that has signs of settlement, the property is of solid stone construction with some quite large stones, e the lintels are 36" by 8".

These have showed sign of cracking, the crack is the height of the stop but does not appear to be all the way through. I have been speaking to a builder who I casually know and he has suggested that he has seen three ways of fixing this. These are

1. "Stitching in" - This seems to be placing steel bars above the cracked stones so that they then take the weight of the structure and hence no additional weight on the cracked stone so they wont get worse.

2."Stapling" - cut about 4 inches off the front of the stone and then fire in staples which will stop re-enforce the stone and prevent the cracking getting worse. The 4" that were removed are replaced by a stone mix which faces off the repair.

3.Replacing the stone is also an option but have you seen the price of stone these days !!!

Anyone done any of these ? If so comments appreciated...in fact any comments appreciated,

Cheers l.c

[RobertL]

before you start patching it up, are you sure the movement has stopped? if it is still moving perhaps there is a leak in the drains or water supply pipe somewhere. if this is movement that took place soon after the house was built then that;'s one thing, but it it has started recently then in most cases subsidence is due to water leakage (washing out the finer grin materials from the foundations. This needs to be fixed.

Robert

[l.c1]

Fair point, there are no new crack that I can see, the plaster is still on the walls plus windows, doors etc look okay. These wall are beside a concrete walkway and there are no signs of bits falling off or moving. I might buy some glass straws though !! Cheers L.c

[fred]

In article , [e-mail] writes

None of the above but I found recently that one of my sandstone lintels had been repaired by resin injection and a very nice job it is too. It looks as if the lintel was given some light support underneath with a flat steel plate of approx 8mm thick and about half the width of the lintel, placed at the back so as to be unobtrusive. The crack, near one end, was resin injected and the face re-finished to match the sandstone. It was such a good job that I hadn't notice until I was replacing a casement on that window. Highly recommended.

In contrast I've seen some really cheap and nasty repairs done on sandstone lintels, some with 8mm angle, yug.

What's the stone type?

[l.c1]

The building is Sandstone - Resin injection ... Hmmmm I will need to start googleing this stuff !!! Cheers Fred.

[fred]

Differential settlement on sandstone buildings is an uber common source of cracks, particularly on mullions and lintels, loads of concentrated stress on a soft material. Many can remain stable for decades but there are situations where a proper fix is required. If you are near a major city with lots of sandstone buildings then that would be a good target location for your search for repairers, it really is a specialist job.

Good luck

[mail]

Dear l.c

Outside my direct field but I do have some experience of this on site. consider various options and points

1) the "end" of the crack should be drilled as a stop point of the stress point - this may be difficult to determine let alone do in practice but the issue should be considered 2) helibars can be drilled through the lintel if there is close enough access from the side 3) the load above can be taken off it with reinforcing as you suggest

- I have in mind stainless steel bars set in mortar but to do this you may have to needle pin and/or provide connections on the bars by doing it in sections

4) a flat metal plate under as has been suggested but this would be visible 5) rebuild an "arch" above ( over expensive)

I would avoid like the Plague any use of resins with sandstone despite glowing comments on two grounds a) not reversible - a good principle to apply to any conservation repair b) such dissimilar materials with repect to water movement and concommitant freewze thaw cycles

Chris

[meow2222]

You're in luck, its not usually necessary to do anything. Lots of old properties were built with no lintel at all, and catastrophic failures are very rare, though cracking is common. The lintel is normally a backup device rather than the primary support. Although a split lintel has much less strength than a whole one, there are still 2 mechanisms in operation that continue to give it a backup support role.

1. An 8" high lintel would have to move sideways in order to mvoe downward, just like an arch. Arches are pretty stable, 8" split lintels ditto.
2. As the lintel ends overlap the window edges, there is a lever effect in operation - for the centre to drop, the brick/stone above the lintel ends would have to rise up, and that just isnt likely to occur.

If its a big wide opening you may need a repair, but in most cases its not really an issue.

As an illustration of the lintel's backup role, I still remember a large house built with no lintels anywhere, not even over the double width garage(s). Decades later the only issue that cropped up was some cracking to a garage that needed repair.

NT