How to securely protect the chimney on the roof from leaks

The brick chimney is the weakest point in the roof of any house. Condensation is the enemy of brick.

There are ways to protect against leakage and condensation at the points of abutment with the roof: to install flashing (internal galvanized) or external decorative.

Ordinary roofers stop at this, but not those who know how to properly install roof windows. They are the ones who know about the third or rather the very first salary. It is called flexible and is made from a waterproofing film or fabric.

Let's start from the very beginning of installation - lathing. When you go around the pipe with a film, it is imperative to leave flaps of at least 10 cm on each side, and make the cuts at the corners as tight as possible to the pipe.

When installing the lathing itself, you need to bring the board to the side of the pipe so that there is no more than a centimeter gap between them, to the upper and make board inserts with the same gap to the lower walls, and stick the patches to the brick wall and grease all 4 corners with sealant.

Advice for choosing a sealant: you need to apply a bituminous sealant for external use for roofs and facades. He is not afraid of sudden changes in temperature and bad weather conditions, which means he will not fall off after a while, allowing moisture to penetrate under the salary.

The flexible flashing is made of hydro-repellent foil or fabric. The width depends on the distance to the rafters closest on both sides, but not less than 40 cm and the height is 10 cm. You need to start from the bottom wall of the pipe, this is the rule for all three types.

The length should be such that on both sides of the corners the frame crawled out by 40 cm. Nail the wide part with a stapler to the board and fix the top with a sealant, then make cuts with a knife from the corners at the bottom, leaving a flap 1 cm in height and from 40 cm, leave 10 cm to glue to the side walls and bypass in the same way as the bottom and glue the upper and lower flaps to the upper and lower walls.

The upper piece of the frame differs from the previous ones: its length depends on the distance between the rafters closest to the sides of the pipe, and the width to the nearest lathing.

Next, you need to carefully cut out pieces of counter-lattice from both sides in the opening between the boards behind a pipe about 20 cm long for access to the waterproofing and make a slot in the span between the rafters and then push the wide part of the frame inside slots.

Next, insert the "dropper" (a piece of galvanized steel with a length equal to the slot in the film, 10 cm wide and curved centimeter tip) between the film of the frame and the crate at a slight inclination to either side and from above we nail down with small nails.

After thoroughly grease all the joints and the top of the flaps adjacent to the pipe with a sealant, if this is done badly, then the entire salary will not work effectively. Such a seemingly tricky flexible flashing system is used when installing skylights for drainage from the upper wall of the pipe and the corners of condensate that will form on the waterproofing along the entire slope roofs. Especially a lot of it is formed in insulated attics due to the temperature difference.

If everything is done according to this instruction, then we get rid of another reason for the appearance of moisture inside the attic, and then you can proceed to the installation of galvanized and decorative frames. I hope this advice will help you build your home and may it always be dry and warm.