Hello I’m Colin Braithwaite and this is my son Philip, we are from Braith-Heritage supplies. we are working with sustainablebuild.co.uk, and we are going to give you a short demonstration on lime pointing.
What you will see now is Philip chipping out the pointing. What we try to do is get it back down about 10mm; this will allow the new lime mortar to key in.
Here we see Philip spraying the wall, you must wet it continuously. What we don’t want is the wall sucking the moisture out of the lime mortar.
What we are going to do now, there is a big void in there so we put some lime mortar in and some pinning’s, and what your doing is ramming it back in. (Pinnings are bits of stone, that’s what we call pinning’s it is a trade name.) More lime mortar, more pinning’s and keep ramming it back in until you fill the void up until you can get no more back in.
You can use any trowels that you want that you’re comfortable with. As you can see Philip is using the bucket trowel to hold the lime mortar. You could use a hod, a brick trowel, whatever you have to hand use that and get comfortable with it.
Usually if you can get your finger in you would put a pinning in like Phil is doing now, because you don’t want to fill them with lime mortar, you want to fill them with pinnings. It’s as easy as that. Then when he has filled them with pinning’s he will put more lime mortar on top of it.
Also what we are looking for is to fill it proud, what we want is the lime mortar to become proud above the stone. There is a reason for that we will show you later.
You would leave that for 24 hours let the air get to it to dry slightly. Come back 24 hours later and you will stipple it with a brush, what Philip is going to demonstrate. The idea of this is your beating the lime mortar back into the wall to consolidate it. It’s as easy as that. Just beat it back in and what your looking for is you don’t want any airline gaps at the top of the joints.
The idea is that the water runs down on the pointing and carries on down the wall; you don’t want it going back in the joints.