Stormdry Repointing Additive No.1 - Wall Repointing - Breathable Protection Against Rain Penetration

TK-SP STORMDRY REPOINT NO1 500

Joints should be raked out squarely to a depth of twice their width. This should result in a depth of approximately 15 – 25 mm, and never more than 35 mm. The joints should then be brushed out to ensure that the repointing mortar can form a good bond.

After shaking the bottle, Stormdry Repointing Additive No.1 should be diluted with clean tap water in the ratio 1 part Stormdry Repointing Additive No.1 to 9 parts water by volume. Higher concentrations are not recommended. The resulting gauging solution should be added to the chosen mortar mix to attain workability.

To avoid shrinkage it is important to add the gauging solution carefully to ensure that only the minimum quantity necessary to attain workability is used. Once mortar has started to set and has become unworkable it should not be reworked by adding more gauging solution. For this reason, only small batches of mortar should be mixed at a time.

Before the repointing mortar is applied, raked out mortar joints should be wetted – e.g. by flicking water using a wet brush. The repointing mortar should be applied into the raked out joint using a suitable pointing iron or repointing gun and tooled firmly. Where deep mortar joints are being repointed this may need to be done in two stages to achieve good compaction.

Wherever possible it is beneficial to tool the mortar to a “bucket handle” finish as this provides the best durability and weathertightness. The curing time will depend to a large extent on the chosen repointing mix (e.g. mixes containing cement will cure more quickly than those based on pure lime). During the curing period mortar should be protected from frost and should be prevented from drying out too quickly. In dry, windy or warm weather it may be necessary to spray the surface of the wall occasionally or cover the wall with damp hessian to allow a proper set, particularly where a lime mortar has been used.