Windows

[quad121]

Hi i wonder if anyone can advise on what to do with the sandstone surrounding the windows as they are not very smooth?

 

[quad121]

Also there are small gaps between the window frame and stone about 10mm can I just fill these with burnt sand mastic or do I need to use some lime plaster?

 

[Roger H]

Hi i wonder if anyone can advise on what to do with the sandstone surrounding the windows as they are not very smooth?

If there is some surface erosion but the stone is still doing its job structurally I would suggest you regard it as patina and leave it be. Is the paint perhaps trapping moisture in the stone and causing some delamination? If so, perhaps a poultice strip removal of any existing impermeable paint, and then repainting with something genuinely breathable.

If the gaps between stone and window are largish, maybe a lime mortar coloured to match the stone - lithomex? If just 10mm, sand mastic as you suggest.

 

[quad121]

Many thanks

 

[bobby spray]

traditionally hairy lime plaster was used to fill the ingo. this was then covered with a bead of burnt sand mastic. Nowadays I use hydraulic lime mortar to fill the gap. I have used lithomex to repair erosion in around windows but yours don't seem that bad.

 

[quad121]

I've been using hydraulic lime and sand to repair a internal wall which the po had used cement which when removed the wall was wet and had a strong smell of damp

 

[quad121]

When trying to apply the lime mortar tithe gap between the window and surround it falls out! Is their any way of preventing this from happening?
On one side it filled fine but the other side it just wouldn't stay in

 

[bobby spray]

I pack it with damp news paper. It gives the mortar something to attach to and the moisture prevents the mortar from drying out too quickly.

Good luck

BS

 

[Tony.]

Or a tub of trowelling mastic?

 

[quad121]

Thanks Tony
That's a good idea using the paper

 

[Roger H]

When trying to apply the lime mortar tithe gap between the window and surround it falls out!

If you catch the lime mortar at the right it should ball up nearly like clay and can be packed in without falling. Then let it go off half a day and press it in a bit more to compact the joint, adding more if needed to bring it flush.

 

[quad121]

Hi and thanks again. I think the newspaper idea would be better. As the sides of the gap are smooth so the mortar doesn't have anything to grip to.