House plinth

[Babaganush]

Hi all,

Our plinth looks like this (see pictures).

What is it made of? What can we do to improve it? We were thinking of removing the old paint, clean it (don’t know how), repoint it with lime and lime wash it.

Any suggestions?

Cheers

 

[JohnD]

It is painted black, and was probably applied to hide (it does not cure) wet brickwork.

Start by scraping away the gravel to see how wet the ground is. It might be wet near pipes and drains.

Look at the wall and find the original DPC. What is its height, relative to current ground or paving level?

 

[Babaganush]

Thanks JohnD

I should have added that it’s not causing damp issues. My question is: what material is under the paint? Is it bath stone? Would scraping, repointing and painting it again be a good idea?

 

[JohnD]

I can't see from your photos what your house is built of, or where the DPC is.

Plinths are very much associated with damp, hence my interest. Most often they are made of hard cement mortar. They are better left unpainted so damp can evaporate off the surface.

The plinth must not bridge the DPC so you need to find where it is.

You may get some clues from nearby similar houses.

 

[freddiemercurystwin]

Plinths like this are commonplace down this neck of the woods, often painted black here too they seldom seem to give problems. Provided the render or mortar is good it will be fine, it does look like in places the plinth is delaminating so it needs some further investigating as to whether it can be repaired or needs hacking off and reapplying. A few taps of a hammer (or just a knuckle usually) can often tell if it's loose or solid.

 

[Babaganush]

Plinths like this are commonplace down this neck of the woods, often painted black here too they seldom seem to give problems. Provided the render or mortar is good it will be fine, it does look like in places the plinth is delaminating so it needs some further investigating as to whether it can be repaired or needs hacking off and reapplying. A few taps of a hammer (or just a knuckle usually) can often tell if it's loose or solid.

Thank you! Do you think it is made of cement? How would I go about repairing it?

 

[Babaganush]

I can't see from your photos what your house is built of, or where the DPC is.

Plinths are very much associated with damp, hence my interest. Most often they are made of hard cement mortar. They are better left unpainted so damp can evaporate off the surface.

The plinth must not bridge the DPC so you need to find where it is.

You may get some clues from nearby similar houses.

Thank you.

The house is rendered at the front and side and has some cladding at the back. It was built in the 1930s and has solid walls. I assume there are stones under the render?!?

Once we scrape the old paint and clean it, can we apply a layer of mortar? How do I know if it’s cement or lime?

 

[JohnD]

If you can scrape it off with your fingernail, it's lime.

The colour tends to cream rather than grey.

1930's houses were usually built of bricks, and had a DPC, usually slate but sometimes bituminous or metal.

There is a good chance you will be able to see the original DPC when you get the plinth off, though it may have been submerged beneath later paving or ground, which is a mistake needing to be rectified.

 

[Babaganush]

If you can scrape it off with your fingernail, it's lime.

The colour tends to cream rather than grey.

1930's houses were usually built of bricks, and had a DPC, usually slate but sometimes bituminous or metal.

There is a good chance you will be able to see the original DPC when you get the plinth off, though it may have been submerged beneath later paving or ground, which is a mistake needing to be rectified.

Thank you! I’ll try the fingernail test. It looks cream and not grey so hopefully it’s lime.

We can see the bricks in the subfloor, however the back elevation of the house seems to be made of stones and some sort of stone cladding (probably not the right terminology). Could you help us understand how it is made if I send over some pictures? I think the blown cladding is causing damp and we are trying to figure out what to do (see my other post).

 

[Babaganush]

If you can scrape it off with your fingernail, it's lime.

The colour tends to cream rather than grey.

1930's houses were usually built of bricks, and had a DPC, usually slate but sometimes bituminous or metal.

There is a good chance you will be able to see the original DPC when you get the plinth off, though it may have been submerged beneath later paving or ground, which is a mistake needing to be rectified.

So we had two builders coming to see our plinth. One says it’s lime render/sandstone and the other one feels it’s a bath stone.
Which is it?

 

[Alastairreid]

Bath stone.