Products for mortar pointing around windows and doors
You can use our lime mortar for joints around windows, doors and other junctions, basic pointing of masonry and repairs of joints in the masonry where lime mortar has been used.
Joints around doors and windows must be able to coorperate with the house without cracking. Therefore, it has to be very elastic but still be strong enough to adhere to the frame or masonry. To achieve this elasticity, we recommend that you use Rødvig Jurassic mortar KKh 35/65/500 and mix cattle hair into it during the mixing. This will make the mortar flexible and strong at the same time.
When repairing joints made of lime mortar you should try to apply the same mortars of the same type and strength. However, it will typically be the relatively strong Rødvig Jurassic mortar KKh 20/80/475, unless it’s a very old building where slaked lime has been used. Before repairing, the joints are cleared of mortar spatters, dirt or the like. You might have to scrape the joints into firm mortar, of at least 3-4 cm, after which a re-pointing is done.
Essential elements for a successful result
1. Windows and doors must be of a good quality, so that they do not shrink or warp.
2. A milled mortar groove approx. 10 - 20 mm on the inside of the outer side of the casing, is an advantage.
3. The distance between the windows/doors and the masonry should be around 10 mm.
4. Tarred flax must be filled at least 30 mm from the outer side, and should be stamped so hard that it creates a firm base for the mortar without putting too much pressure on the casing frame.
5. The mortar is mixed in a compulsory mixing machine together with a suitable amount of water, for 20 minutes until it becomes plastic. The mixed mortar should be used within approx. 2 hours.
6.You fill in the mortar with a jointer until the mortar is about 10 mm. from the outer side. After a suitable drying-out period (about half an hour) the joint is compressed thoroughly, and the last 10 mm are jointed, compressed, burnished and leveled out nicely. When it has dried out, it is brushed with a dry brush.
The work must not be carried out during periods of frost. During the hardening period, the work should be protected from sun and wind.