Coving/cornicing repairs

[Alfietinker]

Sorry, me again - I'm on a house renovation mission!

We have some beautiful coving/cornicing (I'm not sure which is correct), which has sadly been butchered when central heating was installed. We want to decorate these rooms soon, and we would like to make-good somehow.

Is this a DIY job, or expertise only? Where to begin?

Re-routing the pipes isn't an option, and to be honest I'm not sure where they could be sited without going through coving anyhow.

All comments much appreciated!

 

[Alfietinker]

Someone has attempted to replicate the pattern around the bay window addition, and although the photo doesn't really show it, the lines are wonky and full of fingerprints and stands out like a sore thumb. I don't want to make the same mistake.

 

[Clockmaster]

We had more or less the same sort of work in our previous house, a three bed Edwardian semi. Me being big on period features, I disconnected all wiring and piping and used a masonry bit to mark out channelling before using a keen chisel, so I could eventually bury everything. I also removed more plaster around the channels I had created to enable some armour in the shape of 2mm stainless steel plate to be placed over my work to keep it safe. I built up "footings" out of plaster to more or less the level of coving before finishing off using a selection of plastering trowels and filling knives, depending on where the levels were to bring it level with the original coving. Some would say I did it wrong, but this sort of work is not an exact science in my eyes, and we have to make good with what we have on hand (as they also did Centuries ago) I did finish off with a medium sanding paper using a wooden block as a level. This is a dusty process, so use a mask, or in my case, the other half underneath with a vacuum! As regards the picture rail, I removed the damaged sections and sent a small piece off to a wood working shop which made new sections to the moulding I supplied. This was a shade pricey, but considering they had to make a router blade to suit, it was money well spent. All looked good afterwards using period colours to suit. It was more time consuming than anything else. If you have a bit of knowledge and common sense, I'm sure you could make it all good again.

 

[Feltwell]

Are you sure that's pipes? Looks more like cable trunking to me from the size of it, although the picture could be deceptive, or it could be microbore small diameter heating pipe I suppose.

I'm not sure what you want to do here. It's definitely possible to repair that cornice, but to do so you have to get rid of the trunking and hence the cable/pipe within it.

A cable is simpler - you can bury that in a chase in the plaster of the wall, and I've found I can often get a very long masonry drill bit up behind the cornice to feed it through to the floor above - or if the cornice has a big hole in it already you can bury it in a chase before making good the hole.

Pipes are trickier. I've got rid of some visible pipes here by running some down the inside of a big built-in cupboard in the kitchen, then under the sub-floor, then back up to radiators in the lounge and dining room - with the pipes well insulated and a drain point beneath the floor, to which I have permanent access, installed.

 

[malcolm]

If the surface is good one side of damage you can get a long way with a 12 inch steel rule - prepare the surface to about 2mm below level and then use a very fine plaster or a filler. Hold the rule on good plaster for a guide and following the profile drag it around the wet plaster to form the shape.

Originally they would have formed the cornice by running a mould along it's length. If you had a long length to repair it would be worth making a mould from sheet metal or something stiff and using that to shape the plaster.

Shame about the heating pipes. Would have been nicer had they created a magnificent services box in a corner somewhere and then run them under floor. Probably was too much effort.

 

[Alfietinker]

Thanks all.

Yes, they are the central heating pipes - microbore.

I've been thinking about this more and more, and we have been mulling over the idea of replacing all the radiators, as they are all inadequate for the rooms and in the wrong places.

So, I guess the only way to repair, would be to chase them into the wall and make good over the top. From Malcolm and Clockworks description, it is doable. But, it would need to be ripped out again if/when the pipes are replaced.

Which has just led onto hubby and I discussing whether it might be feasible to replace them sooner rather than later.... Which has led onto 'shall we bite the bullet and look into loans to get the big jobs done, rather than saving for 5 years..... Mmm, not sure how I feel about that, but then again, freezing winters aren't much fun either....

Either way, it looks like there's not much point trying to repair as they are.

Thanks all!

 

[paulc]

So, I guess the only way to repair, would be to chase them into the wall and make good over the top. From Malcolm and Clockworks description, it is doable. But, it would need to be ripped out again if/when the pipes are replaced.

Central heating pipes shouldn't need replacing for a very very long time. My CH plumbing is over 40 years old and still good (all copper pipe). I've taken the opportunity recently to chase out a couple of walls and bury the pipes behind the plaster. Sleeved in 20mm conduit, it will be possible to replace the pipes if needed - Simply unsolder the joints top & bottom, and pull the pipes up through the floorboards upstairs.

With microbore pipes, you would be able to get away with smaller conduit and have the advantage of fitting recessed wall boxes with a faceplate behind each radiator. That would make for a much neater job and still allow the pipes to be replaced if/when needed.... Personally, I would switch to sleeved 15mm pipe chased in to the wall and use a wall box without a faceplate. It is going to be a very messy job if you do decide to chase & bury.

 

[Alfietinker]

So, I guess the only way to repair, would be to chase them into the wall and make good over the top. From Malcolm and Clockworks description, it is doable. But, it would need to be ripped out again if/when the pipes are replaced.

Central heating pipes shouldn't need replacing for a very very long time. My CH plumbing is over 40 years old and still good (all copper pipe). I've taken the opportunity recently to chase out a couple of walls and bury the pipes behind the plaster. Sleeved in 20mm conduit, it will be possible to replace the pipes if needed - Simply unsolder the joints top & bottom, and pull the pipes up through the floorboards upstairs.

With microbore pipes, you would be able to get away with smaller conduit and have the advantage of fitting recessed wall boxes with a faceplate behind each radiator. That would make for a much neater job and still allow the pipes to be replaced if/when needed.... Personally, I would switch to sleeved 15mm pipe chased in to the wall and use a wall box without a faceplate. It is going to be a very messy job if you do decide to chase & bury.

Sorry, I meant replacement if we re-site all the radiators and the pipes needed moving. Mess and disruption I can deal with if it means it doesn't need doing again. We are going to get the plumber to quote for all the radiators that need doing and if we can stretch to it, just bite the bullet and get it done. We've had bare walls for 2 years so waiting to decorate is no great shakes. We can do a lot of the chasing-in ourselves to save labour costs if so.

I hear mixed things about microbore, but the system is a mixture of both. The previous owners had a nice shiny new boiler, but ancient, tiny radiators and a hotchpotch of piping.

Either way, I now realise the only way to fix the coving is to chase the piping in - there's no quick fix.

 

[paulc]

Either way, I now realise the only way to fix the coving is to chase the piping in - there's no quick fix.

While you are making a mess, perhaps consider chasing in conduit for extra sockets. Oh, and while on the subject of burying pipes in walls, make sure that there are no joints in the hidden pipes. If it is a choice between using several short lengths or going out and buying a full length, go for the latter every time.

 

[Nigel Watts]

Deciding where the pipe runs should be is the first thing to consider. Usually its best to have them in the hall or staircase where they can be boxed in relatively unobtrusively rather than coming through the ceilings of the main rooms. Old houses often have hollow walls (stud walls with lath and plaster) and hollow floors so there is scope for hiding pipes too.

Cornice repairs are possible even by amateurs but you need to use the right materials. Modern fillers are not great because they are too sticky. It's a while since I have done this, but I found a mix of plaster of paris and lime putty can work quite well (this is what they would originally have been made from) but you need to be patient and practice a bit. The ground needs to be well wetting first and layers are best built up gradually. The mixture shrinks, so it needs to be pressed in well while drying. They are levelled off using steel rules.