Pointing old stone wall

16 Replies

Hi. I will be repointing one of my house wall in a few weeks. In some places there is a gap (around 3 inches) between top of the wall and the roof timbers ... which I'd like to close to make the house more weather proof (and rodent proof). Was thinking of using some expanding foam to fill gap ... then finishing off with pointing material (sand & lime mix). Does this sound OK? Also should I insert some vents for ventilation? Thanks.

Featured Classified


chèvrefeuille 1454432502

I have always built up the gap with stone and lime mortar.

Ronnie2-606556 1454444867

We're doing the interior walls of our barn right now. Building up to the top with stones, sticking them in with lime mortar and repointing the entire wall with a local sand/lime mix - 3:1

It's heavy work getting the stones up the scaffolding, but the walls look a treat...


chris e-576341 1454448957

Stone with sand and lime ( chaux)  mix five to one.

cardi-512727 1454454158

For modern houses with restricted ventilation it may not be a good idea to point internal walls with a mix that allows inward breathing unless you ar certain the wall is constantly dry.

I do a 3:1 mix sand:hydrated lime for external walls but internally a 9:3:1 sand:lime followed by a PVA wash to seal and prevent dust rumble. Some prefer quicklime.

As said just do a mortar mix and shove stones in the gap  as you go along

woodbine-561816 1454456591

Thanks for your replies. I'd thought using expanding foam would save a bit of time ... but I'll go with stones and mortar as suggested.

dave&olive 1454457687

Hi ok

 If you have not used lime before ..stay away from it ..it`s the wrong time of the year to use it  . try renocal  mixed 3.5 / 1   


Bonne chance


rollerboy 1454494913

Hello woodbine - do not use expanded foam to fill gaps - it will certainly not keep rodents/critters out. Stone and lime mortar (careful with the lime!) is the answer, as already suggested. We used a commercial product called 'Multibat' quite successfully, too. It allows the joint to breathe.


chris e-576341 1454496814

There is an awful lot of different mix advice here. If you use too much lime it will create a mix that is too strong, which is just as bad as a weak mix. Most lime morters are packaging states the correct mix ratio for each particular situation.

if you do not want to use a full lime morter then a product called tradifarge from leroy merlin is good. It contains mostly lime but has other additives that make it easier to use. You will need to check the store that you keeps it as not all do.

The thing that bothers me, is I do not know your experience in doing this sort of work. Everyone has to start somewhere, so , basically find stones that are a similar size and colour to fill the gaps and place them without mortar to see how they look. You can get a clue by what is next to it. If you put in one stone where the courses on the wall dictate two it will look odd.Try to find some very small pieces that can be used to fill small gaps between your new stones for stability. If you look closely at your wall you will see how the french use shards of stones for this.Once you are happy take them all out and keep them in an order so you can reassemble them easy.Next make a decision about the mix ratio you will use, and a good way is to look at the advice on the lime mortar packaging As the reputation of the company that produces it rests on that.Try to avoid off the shelf one size fits all ready mixes. 

Add water slowly. Dont mix too much at one time. Let it reat a bit beteen adding water and applying.Add water slowly so it is firm but pliable. Use the morter to fill the gaps, but not like you would lay bricks. French walls have more in common with dry stone walls in the uk than brick walls.The little stones are used to add stability. Try utube for all the above as seeing is easier than saying. Good luck. 

With pointing, there is an easy way to do that. Use a lot more mortar between the joints so that just before it dries completly, you remove the excess mortar with a wire brush and you have a perfect joint.

Google pointing stone walls.

One last thing. If you don't like the result, take it apart before it dries and  try again

woodbine-561816 1454528866

Thanks for your help. I'll use mortar / stones as suggested. I won't be doing the work till March ... so I guess using a sand / chaux mix will be ok. 

peche100 1454530209

Expanding foam is a brilliant solution, don't be frightened of using it. Like all things it needs some experience to get it where it needs to be. But it expands like mad and given time to set can be carved into place and will take a final render easily.


barryandpat-550891 1454530248

Like they say use stones to fill the holes, but use white cement and fine stone colored sand, lime not nessesary cos its in the cement.

When we started on our house there were 6" gaps and more, so we used grey cement and stones for strength then a mix using the above. The original owner who was a brickoleur French artisan made a pigs ear of some of the repairs, so we did it right as per logic and Isle of Man lime stone.



Ronnie2-606556 1454530315

Nice one peche, have you seen it after 10 years?? I really wouldn't want my wall held together with it..

barryandpat-550891 1454539352

Still here 11 years later.

barryandpat-550891 1454539472

He`s talking about pointing not building.

barryandpat-550891 1551962737

still here

barryandpat-550891 1558971676

still no deterioration since 2007 walls are dry and waterproof.We are very pleased with our choices.

Join the discussion