Summary: How much does it cost to repoint mortar, average labour costs to repoint mortar on a house or wall and average cost of materials.
Over time, weather and decay causes holes to appear in masonry joints (usually mortar), thus allowing water to seep in. Freeze thaw action on this water thus starts a process which can cause significant damage to the masonry. On older buildings the outer aesthetic mortar is often harder than the mortar that bonded the bricks in the first place, meaning that once the exterior mortar has started to erode and crumble, the inner mortar very quickly starts to deteriorate. You can patch a smaller area if necessary but it often makes long term (and aesthetic) sense to do a full grind-out and re-point at the same time.
|Labour (m²)||£25 – £45 (m²)||2019||n/a|
Factors to consider
It is essential that the material used to re-point has the same characteristics as the original mortar; such as permeability, strength and thermal expansion. If the mortars are not compatible there is a risk of serious damage to the structure. A specialist in architectural conservation will be able to advise you on the correct composition for your replacement mortar if you are unsure.
Don’t be tempted to re-point over existing mortar that is damaged – all that will happen is the re-pointing will quickly ‘pop’ off, leaving more work to do. It is well worth the time and effort to rake out the old mortar properly in the first place –in the long run it will definitely save time.
Always work down the wall; this will ensure that any dust, rubble or mortar will not fall on any finished areas of masonry. The consistency of your new mortar is of paramount importance – too wet and it’ll smear all over your masonry, too dry and it will crumble. You need to be able to cut ‘slices’ of mortar that can be used straight into the raked-out masonry.
Costs to consider
If you are hiring a professional to do the work for you, then as well as their labour costs you may have the additional cost of scaffolding or an access tower. Some companies have their own scaffolding but it is best to clarify this before work commences. If you are doing the work yourself, there are several things you need to consider. Depending on the size or height of the area to be re-pointed you may need to hire a scaffold tower. Working from a ladder is inadvisable; it’s uncomfortable and dangerous for this job.
You’ll need a plugging chisel and club hammer to remove the old mortar; soft mortar will need a hook or old screwdriver to aid removal. When removing old mortar don’t be tempted to speed up the job by using an angle grinder or disc cutter as it will only cause damage to the surrounding masonry. Some professional companies use more specialized tools such as diamond blade professional machines, power chisels or mortar raking discs, which all add to the cost. It’s important to get a good surface to adhere the new mortar to, so any hard to reach bits of old mortar need to be removed with a mortar saw or hacksaw blade. You will also need a small dry brush to brush away any remaining dust and a watering spray or wet paint brush to damp down all the joints.
To save money, only mix a small amount of mortar at a time. Re-pointing is a long, slow process so you won’t be able to do much before your mixture goes off. Don’t attempt to re-point if bad weather such as rain or frost is forecast. When replacing mortar you will need a trowel, level, hawk to carry the mortar and some sand and cement. Professional contractors (and careful DIY enthusiasts) can make use of pointing guns which, if properly used can speed up the whole re-pointing process. The mixture needs to be a little wetter, but great care must be taken to ensure the mixture stays consistent and doesn’t separate out in the gun and that all voids are filled right to the back of the hole. Many people prefer the control and consistency a trowel gives them, despite the extra time it takes.
There are many types of pointing finishes, for example flushed, weathered, hollow key and recessed key. Over large expanses of masonry the choice of key could impact on the amount of mortar used and thus the final cost.
Re-pointing is well within the skill level of the average DIY’er and despite the patience and time needed to do it, it will reap great rewards; a well re-pointed house will benefit from an increased property and resale value, enhanced image and increased long term conservation of the building.