How to reliably seal the gap between the chimney and the roof

When the chimney pipe exits through the roof, a gap remains that must be sealed. Since the chimney heats up, ordinary cement-sand mortar is not suitable for this purpose, as it will crack. The problem can be solved on a budget by making a special asbestos-cement mortar, characterized by high temperature resistance.
How to reliably seal the gap between the chimney and the roof

Materials:


  • cement;
  • sheet asbestos (can be used);
  • water.

Gap filling process


To seal the gap, you need to prepare a heat-resistant compound. To do this, you need to tear sheet asbestos into small pieces. Its thickness and condition do not matter.
How to reliably seal the gap between the chimney and the roof

This can be either new or previously used sheet. The pieces are about the size of a thumbnail, maybe a little larger. The flaps are prepared until their volume is equal to half the volume of the required solution.
How to reliably seal the gap between the chimney and the roof

Then cement is added to the asbestos in a 1:1 ratio.
How to reliably seal the gap between the chimney and the roof

The components must be mixed dry.
How to reliably seal the gap between the chimney and the roof

After mixing, add a little water to them. You need to make a thick mixture with the consistency of sealant.
How to reliably seal the gap between the chimney and the roof

The resulting composition is left for 5-10 minutes, then mixed again and applied to the area.Due to the reinforcement with asbestos fibers, it does not fall into the gap. The composition is first applied around the pipe. The more you use it, the less likely it is that a crack will develop in the frozen mortar in the future. But you don't need to use too much.
How to reliably seal the gap between the chimney and the roof

How to reliably seal the gap between the chimney and the roof

If the gap between the pipe and the slate is sealed using an overlay plate, then a slope should also be formed for the water to flow down so that precipitation does not accumulate in the waves in front of the chimney. Before applying the mortar, you need to clean off the dirt and lichen from the slate so that the cement can adhere to it properly. The composition is applied on top with a wet hand or a paint brush dipped in water to make the surface smooth without open pores. If necessary, the remaining solution can be used to quickly repair cracks in slate.
How to reliably seal the gap between the chimney and the roof

After a day, in dry, warm weather, the solution will set almost to the hardness of the stone. After 28 days, the cement will gain full strength, but the chimney can be used even earlier. It is enough for the asbestos concrete to dry, after which you can safely use the chimney for its intended purpose. If you rush, a crack may appear in the wet mortar near the pipe, and then everything will have to be redone.
How to reliably seal the gap between the chimney and the roof

Watch the video


come back
Comment
  • bowtiesmilelaughingblushsmileyrelaxed relaxedsmirk
    heart_eyeskissing_heartkissing_closed_eyesflushedrelievedsatisfiedgrin
    winkstuck_out_tongue_winking_eyestuck_out_tongue_closed_eyesgrinningkissingstuck_out_tonguesleeping
    worriedfrowninganguishedopen_mouthgrimacingconfusedhushed
    expressionlessunamusedsweat_smilesweatdisappointed_relievedwearypassive
    disappointedconfoundedfearfulcold_sweatperseverecrysob
    joyastonishedscreamtired_faceangryragetriumph
    sleepyyummasksunglassesdizzy_faceimpsmiling_imp
    neutral_faceno_mouthinnocent
5+two=
Comments (4)
  1. high voltage
    #1 high voltage Guests 28 May 2020 22:53
    2
    At least something useful.
  2. Howda
    #2 Howda Guests 3 June 2020 13:49
    4
    Author, why did you add asbestos, for reinforcement? For what? After drying, the cement mortar will shrink and cracks will appear. If the pipe heats up too much, it will also crack. In general, no credit.
  3. Guest Alexander
    #3 Guest Alexander Guests 21 August 2020 18:34
    1
    What about the expansion and contraction of the pipe? When heated, it expands and vice versa. Cracks should appear. I also placed the pipe in the sleeve and stuffed the gap with asbestos chips and blew it out with heat-resistant foam.
  4. Sergey K
    #4 Sergey K Visitors 28 August 2020 23:33
    0
    Nothing lasts forever, no matter how hard you try, everything still needs to be changed after a few years.