"Reconstructed stone" repairs

[dandrew]

A previous thread alluded to a masonary problem affecting the portico of my 1850-ish sandstone house. I leaved through the Yellow pages and arranged a few likely masons to come round for a look & estimate. First one made all the right sounds about allowing period houses to breathe, advantages of lime, awful cement mortar and evils of Sandtex etc. All sounded good until he suggested 'repairing' the affected masonary. On further questioning he expounded on the benefits of a 'plastic' repair using this magical stuff that cost £130 per 30kg bag, which is trowelled on, left to set and then shaped in situ. Assured me it was not cement-based and that it was an honest repair (even said he'd worked for EH, NT & Ancient monuments) that would not harm the building. Sounds suspiciously like OPC to me or maybe some sort of epoxy-based material, but I have little real knowledge. Has anyone come across this before ?, if so is it the best way to do things or simply the cheapest/easiest/most profitable ? It sounded too good to be true to me and seems as though it might do more harm than good. Any suggestions ?

David

 

[chuckey]

Mot lintels in victorian houses that look like sandstone are actually ham stone, some synthetic stuff. This isn't ham stone mix in a bag is it?
Frank

 

[Penners]

Most lintels in victorian houses that look like sandstone are actually ham stone

And they're a pig of a job to repair.

:lol: :lol: :lol: :lol: :lol: :lol:

(Well, I have to laugh - nobody else is going to.)

 

[Penners]

David - is it a lintel that's broken? If so, I don't think I would attempt any kind of repair. To ensure the stability of the masonry above the lintel, I'd replace it.

 

[Feltwell]

David - is it a lintel that's broken? If so, I don't think I would attempt any kind of repair. To ensure the stability of the masonry above the lintel, I'd replace it.

It's not always necessary to replace. We have some cracked lintels, which the surveyor advised probably happened in the first 5 years of the building's life, and that they frequently lock in position. As there was no sign of any movement he advised leaving well alone.

 

[Penners]

Feltwell - I accept that under certain circumstances it might be OK to leave a broken lintel in place, but it depends very much on the individual structure. In particular, the nature of the break, the amount of weight that the lintel is carrying, and the extent to which the lintel's width exceeds the width of the window reveal.

But quite often an apparently stable broken lintel is actually being supported by the window frame underneath it. And that could become a dodgy situation if/when the frame deteriorates and needs repairing or replacing.

 

[Gareth Hughes]

A previous thread alluded to a masonary problem affecting the portico of my 1850-ish sandstone house. I leaved through the Yellow pages and arranged a few likely masons to come round for a look & estimate. First one made all the right sounds about allowing period houses to breathe, advantages of lime, awful cement mortar and evils of Sandtex etc. All sounded good until he suggested 'repairing' the affected masonary. On further questioning he expounded on the benefits of a 'plastic' repair using this magical stuff that cost £130 per 30kg bag, which is trowelled on, left to set and then shaped in situ. Assured me it was not cement-based and that it was an honest repair (even said he'd worked for EH, NT & Ancient monuments) that would not harm the building. Sounds suspiciously like OPC to me or maybe some sort of epoxy-based material, but I have little real knowledge. Has anyone come across this before ?, if so is it the best way to do things or simply the cheapest/easiest/most profitable ? It sounded too good to be true to me and seems as though it might do more harm than good. Any suggestions ?

David

"Plastic" (Noun) Horrid petrochemical product used to spoilt the appearance of historic buildings.
"Plastic" (adj.) Able to be moulded or shaped. Therefore, "Plastic Repair" a repair effected in a malleable material (such as lime mortar):

http://www.limemortars.com/pdfs/plasticstonerepair.pdf

 

[dandrew]

Penners - no not a lintel, 1 corbel, 1 6-square piece and 1 string moulding (an inverted ovolo).

Gareth - 'plastic' (adj) rather than 'plastic' (noun). I have my doubts as to whether lime goes for £130/bag and therefore suspect that its something else. A little bit of www searching revelaed that 'reconstructed stone' is synonymous with 'cast stone', which will invariably contain cement. As such I'll be giving it a wide berth and waiting for a proper mason to give me an answer.

David

 

[Nemesis]

Talk to Rose of Jericho.

http://www.rose-of-jericho.demon.co.uk/index1.htm

Plastic repair:
http://www.northwilts.gov.uk/masonry_repairs_web-friendly-2.pdf

 

[Feltwell]

Feltwell - I accept that under certain circumstances it might be OK to leave a broken lintel in place, but it depends very much on the individual structure. In particular, the nature of the break, the amount of weight that the lintel is carrying, and the extent to which the lintel's width exceeds the width of the window reveal.

But quite often an apparently stable broken lintel is actually being supported by the window frame underneath it. And that could become a dodgy situation if/when the frame deteriorates and needs repairing or replacing.

Absolutely - depends on the circumstances, and in fact one of the lintels on my house does concern me as it may be supported by a door drame, which has rot and needs repairing! I just meant that cracked lintels don't always need to be replaced, it's worth getting an opinion before ripping one out.

What appears to be a structural lintel isn't always as it seems - I've worked on a Victorian house before where a cast iron beam was in place behind a stone lintel. The beam appeared to be taking the weight of the wall above, and was hidden from view.