How to Point with Slaked Lime Mortar and the Tools Required
Tools needed to point with Lime mortar
People who point a lot with lime mortar will have developed their own techniques. I personally much prefer pointing with slaked lime mortar, and obviously I only use lime mortar when working on period properties. So this works for me and is by far the easiest method I’ve found to use lime mortar when I’m pointing brick or stone.
Below is a list of the tools and equipment you will need:
WE STOCK ALL THE TOOLS AND EQUPMENT LISTED BELOW AND CAN PROVIDE BUGET PRODUCTS ALL THE WAY UP TO PROFESIONAL S CHOICE . PLEASE FEEL FREE TO CALL OR CONTACT US FOR HELP AND ADVICE.
NB Large bed joints can happen with more rustic properties and Tudor up to Georgian or generally with bricks that were fired in a clamp not a kiln.
(Knocking back refers to softening the lime mortar by kneading it .The slaked lime mortars we manufacture and sell are gauged and ready to use from the tub or bulk bag, but like all slaked lime products they will stiffen when stored or transported and need to be loosened up before use).
Any slaked lime mortar that is dropped can be softened and used again provided it has not set hard. Unlike sand and cement lime takes time to cure and has to dry out completely before it can be considered to have set. However this makes it a more economical proposition than you may think as there need not be any waste.
Always wear protective equipment when using slaked lime and lime mortars, they are caustic.
Good care should be taken of your eyes as well as wearing eye protection I always keep a large bottle of clean water with a lid that produces a jet of water handy. If you do get lime in your eye wash with plenty of water immediately. It is very painful I can say that from experience. Do not rub your eye this can cause permanent damage; mortar has grit and sand in it as well as lime and is abrasive.
HOW TO POINT WITH SLAKED LIME MORTAR
Rake out the joint
It is important that it is clean and free of dust, there are many different tools on the market for doing this and consideration has to be taken as to how hard the pointing is before picking your method.
If it’s very soft you may just need a chariot /mortar rake, with harder mortars there are a variety of attachments to fit on an angle grinder, again we stock one that I have found to be the best. Care must be taken if you are forced down this route, as you may remove some of the brick as well as the pointing; this is especially common with diamond cutting wheels. Full safety equipment should be worn if using powered removal methods, such as dust mask visor/goggles and gloves.
When raked out, the joint should be deeper than it is wide for example if you have a 12mm wide bed aim to rake out at least 16mm.
Wash all the dust out, use a hose pipe for this, I wouldn’t use a pressure washer as lime mortar is soft and can be forced out with the water pressure, I find a hose pipe sufficient for the job. Start at the top otherwise dirty water will mess up the cleaning you’ve done.
Take your time you will be surprised how much muck comes out. It’s important to remove as much of the wet dirt from the brick faces as you can.
Dirty water will cause a pale staining on the bricks that can take a very long time to go if allowed to set. Sometimes if the bricks are very porous staining will be inevitable but its best avoided if possible.
Always insure the mortar bed to be pointed is damp, as the water being drawn into the wall will pull the mortar with it making a good bond, also the mortar will dry to quickly and crack if the wall is to dry.
Place the plastic sheet on the ground as all the mortar that falls on it can be re-used if it hasn’t set hard.
Start pointing at the top and work downward I am left handed so I start in the left hand corner working the mortar into the joint with a margin trowel straight from a bucket trowel .
Many people fill the perps (up right joints) first, I find filling the horizontal joints and the perps after is much better as you can force the mortar into them without it spreading.
Make sure you push the mortar well into the joint, as air pockets in the mortar will fill with moisture that can freeze in winter and crack and blow out in hard frost .
Any mortar that is forced out above and below the margin trowel as you work, should be left until it has hardened a bit before you attempt to scrape it off. It will smear on to the brick face if it is too soft when removed.
When you have got mortar packed well into the bed and the mortar is hardening, at this point there are various techniques you can employ to finish the job;
Lastly stand back and have a look at what you have achieved, it will last for many years protecting the wall from the changing seasons and allowing moisture to wick away.
And it looks good too
If you have any questions about this article or any other aspect of lime work, please feels free to contact us for a chat .