Hanging radiators on stone walls

[Liz Fry]

We have finally reached the plumbing stage of our renovation :lol: and I`m starting to think out the logistics of heating pipe runs and radiator positions.

I keep hearing lots of "lime plaster" horror stories from various tradesman who do not understand the concept of breathability in old buildings etc........ some of these comments are around how impossible it is to hang things off lime as it crumbles.

Can someone put my fears to one side ... and if possible advise on the best way to hang a radiator off a stone wall which will be limeplastered. Should the walls be plastered first and then fixed to.... or is there an alternative way of fixing

Many thanks again

Liz

 

[Moo]

This is a far from expert view, but in your place I'd get all the plastering+decorating done before bolting the radiator firmly into the stone just because it would be more straightforward. With the radiator in place it's possible to decorate, but I can't see how you'd do the plastering.

 

[vicky whitworth]

Hi Liz, I can only empathise. We have rubble stone walls made up of chert which is a glassy stone a bit like flint, and then the walls are lime plastered. Only 10 minutes ago the electrician said to me, "I don't know what to do. I can't drill into the chert, it's too hard. And if I drill into the lime it just crumbles." I'd also be glad to hear from anyone who's found an answer to this. Vicky

 

[Liz Fry]

luckily the cable will be run in conduit before we lime plaster.

Previous radiators were fixed on the cement render that the previous owner had tanked the walls with. The walls were naturally soaked through with damp which is why we spent months knocking it all off. Naturally we don`t want to go down that route again to fix them back on!

Maybe I need to dig deeper into my wallet and get some with feet..................

 

[Moo]

As I was reading your last post I was thinking "a pity that it seems she has already bought the radiators, otherwise I'd suggest getting the ones that stand on the floor".

Then I came to your last sentence......

 

[Liz Fry]

I was due to go out and buy them tomorrow........... now I`m having a rethink!

The other option I`m considering is location. The 400 yr old stone bit of my cottage is one up one down. There is then a 30yr extension bolted on to it. I`m wondering if I could get away with locating the radiator in the old bit on what is now an INTERNAL stone wall and using cement on a small proportion of the wall here to give me a fixing point. The need for breathability shouldn`t apply (I presume) on this wall.

Need to have a good think about this one.

 

[Gareth Hughes]

Utterly bizarre question, as if anything fixed to a wall is actually fixed only to the half-inch or inch or so of plaster covering its surface. Of course it's safe to hang things off a lime-plastered stone wall, the fixings go through the plaster, into the stone. How do you think enormously heavy ancestral portraits stay up on the walls of our stately (and not-so-stately) homes?

 

[GeoffP]

I drilled through the lime plaster and well into the stone and fixed the brackets with 3" screws. Solid as a rock. If the lime crumbles, patch it up.

Geoff

 

[borischarlton]

Liz,

Am I right in thinking that at the moment it is a bare stone wall that is going to be plastered? Are the radiators wall hung or floor standing with brackets at the back to hold them to the wall? I would sort the fixings now before the walls are plastered by drilling the stone and putting in a suitable rawl plug. You can then insert a dawl to keep the hole clear of plaster when it is completed. This method will give you a very strong fixing. If the fixing happens to fall between the stones, ie, in the grout, you can do it the old fashioned way and drive in a piece of wood to act as a rawl plug. I have had great success using these methods in my property.
Good luck
Rob

 

[Liz Fry]

hey, that's why the question was asked. Heard these comments more than once by various tradesmen passing through and thought I would rather know before hand if there was any element of truth to them.

Rob

Walls are currently bare and nice and dry now that all the nasty cement render is off.

I haven`t bought the radiators but had planned them to be the basic wall hung variety.

 

[Wren]

Dear Liz
I had also heard the same thing from tradesman. Also there is a possibility of changing the position of one or more of our radiators in the future so didn't want extra hassle if might be moved eventually anyway. So decided to buy the ones with feet, and also at the same time decided that I actually preferred them to have feet (something unnatural about them hanging in mid air).
These were the ones I got (Ancona radiators with feet), and very happy with them.
http://www.theradiatorcompany.co.uk/radiators/steel_multi_column/ancona_stock.html

If you set a decent sized radiator against an internal stone wall then it will act as a heat sink which sounds like a good idea.

In terms of hanging things on a lime plastered wall we recently put up some curtain poles and also pictures. I was fearing the worst, but didn't have a problem at all.
Most of the time I bet there isn't any problem. Maybe because very occasionally someone hits a hollow bit of plaster and then there are delays etc while it gets sorted out then tradesmen just don't want the risk of any hassle and try to avoid it (but end up overstating the issue).

Good luck.

 

[chuckey]

1, Use 4" screws and 4" plugs after plastering - You'll need and SDS drill + bits for this.
2. Fix 2" X1" battens flat to the wall at the radiator fixing centres (be careful about Lh. and Rh. rad. brackets and their offsets). These can be fixed into any convenient mortar courses (make'm too long high/low?). Plaster them in. Screw brackets through plaster into battens.
3. Fix plugs into mortar/stones on naked wall, stick nail in holes to find them after plastering.
I would not recomend knocking wedges into mortar courses, especially under windows, the stone will come loose. I have had to rebuild under every window in my house because some twit of a plumber used a 14 lb hammer to knock the wedges in and basically, left a shattered wall behind every rad. :roll:
Frank

 

[Flyfisher]

I agree with Gareth - surely no-one fixes anything of any substance to any type of plaster on a wall. The fixings must go through the plaster into the structure of the wall itself. I would worry about any tradesmen asking this sort of question, especially when fixing something as substantial as a radiator to a wall. What were they thinking of using, a couple of 20mm screws?

 

[Jon Maine]

I am also in the Mendips, very lime plastered over limestone rubble walls.

No major problems fixing through lime plaster after it is done into the stone. Ocassionally if you drill straight into a joint it is too "soft " a hole to take a fixing. You may just need larger and longer fixings.

Do you have a lime plasterer lined up yet? If not I can recommend a couple if you pm me.

 

[Andrew Bodenham]

You don't say what sort of stone your house is built from. There is a lot of difference between fixing into granite say, and fixing into a soft sandstone.

Any tradesman who starts mithering about fixings should be shown the door, and I say that as a tradesman. With the range of drilling machines, specialist drill bits and innovative fastenings now available there is absolutely no excuse for fixing problems. The fact that it's lime plaster is neither here nor there - as other posters have pointed out the fixings go through the plaster layer into the underlying stone / brick / whatever.

The houses round here do provide some challenging fixing situations. Often it's random rubble limestone (v.hard) bedded in lime mortar which is little more than limey soil. The usual thing is for the drill bit to skid off the side of a stone into a powdery void. However, I've yet to encounter a fixing problem that couldn't be resolved with a bit of ingenuity and decent hardware.

My secret weapon are Multi-monti screws (sold by Screwfix). These are very high quality masonry screws which go directly into a drilled hole without the need for a plastic plug. They work in a range of materials (I also like to use them in timber) and develop exceptional holding power. They're my fixing of choice for heavy things like rads.

The multi-material drill bits by Bosch and others are also useful. I use these for drilling through fragile lime plaster without percussion, where the heavy impact from an SDS machine would likely cause damage.

 

[Jon Maine]

You don't say what sort of stone your house is built from.

We of the Mendips have 99.9% of our traditional housing stock limestone if stone built. Fortunately relatively easy to work although it comes out the ground in many forms all around the Mendips.

 

[Andrew Bodenham]

Jon Maine - I was directing my comments towards the original poster, Liz Fry. I should have made that clearer in my post.

 

[Jon Maine]

I am sorry you feel that way, I happen to know where Liz lives its a 10 minute drive from my house and happen to know the local geology is limestone with a belt of sandstone along the ridge where the limestone has worn away. She is relatively near the statue of Romulus and Remus for interests sake built by Italian POW around 63 years ago which is very interesting.

http://www.mendip.gov.uk/NewsArticleL.asp?id=SX9452-A7824936 .

I have not questioned your advice or seen the need to add to it, it all seems thoroughly sound to me although as we both know there can be more than one way to skin a cat. I would also say I am unsure of your local geology and if the need arose would hope you could advise me. Please remember that this is a public forum and whats the difference if someone else has the answer earlier so you can respond more promptly?

 

[Feltwell]

Ref. Andrew's post - I didn't know you could use those Multi-Monti screws in wood. Why would you want to do so though? Just curious.

I agree they are very good (if expensive), I used the flanged hex head versions for securing cast iron downpipes on my house. Much better than pipe nails, you can take them out again if necessary with no problems and once the heads are painted black they blend in just fine. They also seem to work well even if drilled close to the edge of a brick or stone - they don't seem to generate much expansive force, unlike a conventional fixing which would break the brick or stone.

I've a load of new "cast iron style" (real thing just too expensive ) radiators to hang. I hadn't thought of using the multi-monti screws, so thanks for that, they will be ideal.

 

[Liz Fry]

Yes limestone. Sorry would have responded earlier however have been without Internet all day.....