Keep your home safe and dry: Tips for preventing water infiltration through roof joints

Protect your home from expensive water damage: Inspect your exterior roof joints regularly

Joints, which are applied at the junction of the various elements of your home’s exterior envelope, should be inspected regularly, ideally in the spring and fall. Take the time to closely examine your roof and around doors and windows to make sure that the seals are in good condition.

Fixing Roof Seams Before It’s Too Late

The joints of your roof are defective are often caused by:

  • the use of a poor quality sealant
  • poor application
  • poor compatibility of the sealant with the surfaces to which it is applied.

Do you find that your roof joints are cracked or loose? Repairing them is a simple and inexpensive operation. And it’s best not to delay: losing a seal can result in significant costs. Don’t forget that:

  • Water infiltration damages siding and insulation, as well as the structure of the house;
  • Air infiltration increases your heating bill and causes discomfort during the cold season.

Choosing the right sealing product

Before selecting a sealant, be sure to read the product description and application instructions on the cartridge. This will give you crucial information and let you know right away if the product is suitable for your building.

You should consider the following:

  • Compatibility between the product and the surfaces to which it will be bonded: the surface to which the sealant will be applied (wood, metal, masonry, glass, etc.) will determine whether you can opt for latex, silicone, elastomer, polyurethane, etc.
  • Elasticity of the sealant: it must remain flexible and stretch to adhere to surfaces, regardless of weather conditions. And, in Quebec, since we are particularly well served in terms of temperature variations, this criterion is by far the most important. You will find on the market sealants whose flexibility and elasticity are guaranteed at temperatures down to -40°C.
  • Other product qualities: ease of application, application temperature range, drying time, VOC content and toxicity, drying shrinkage coefficient, adhesion, viscosity, color, UV resistance, paintability, etc. are all characteristics to be considered.

The cost of the product depends on the qualities of the product. A more durable product will obviously cost more. But the investment is worth it!

Apply the sealant yourself or hire a contractor?

If you have good manual dexterity, which is essential for handling the applicator gun, and if you are confident enough to make uniform and aesthetically pleasing joints, you may decide to apply the sealant yourself.

However, there are a number of factors that may prompt you to seek professional help, including

  • a significant or extensive preparation work
  • an application that must be done at height
  • a greater or lesser degree of competence in this type of work.
  • A professional will usually use a high performance sealant and will have developed sufficient skill to make impeccable joints. This is a good value for which you will have to pay a few dollars.

Surface preparation: an essential step

Before applying a new sealant, you must:

  • Remove existing sealant: a joint made over an existing joint can be unsightly because of its excessive width and not very durable because of insufficient sealant thickness. If the old sealant was bituminous in nature, it could be diluted by the solvents in the repair sealant and stain the sealant. If the sealant is silicone, the application of a different product could affect its adhesion.
  • Clean surfaces thoroughly: dust and contaminants can reduce sealant adhesion. Choose a cleaner that is appropriate for the surface and the deposits on it: dust, wax, grease, oil, mildew, etc. Remember to follow the product manufacturer’s instructions and allow the surfaces to dry completely before applying the new sealant.

Durable, high-performance roofing joints

The longevity and performance of seals are directly related to the following characteristics:

  • The width of the contact surface of the sealant on each of the elements to be joined: the larger the contact surface, the better the adhesion and durability of the joint.
  • The size of the gap to be caulked: if the gap is greater than 6 mm (1/4 in.), a foam bead should be inserted to provide adequate support for the caulk and prevent it from sinking. In the case of a very wide joint, take the time to check it the day after application to make sure it hasn’t opened up. In this case, add sealant.
  • The maximum and minimum joint dimensions, both in width and depth, must be respected according to the product manufacturer’s specifications. Each product has its own characteristics.

Finally, if you choose a sealant with a high solvent content, such as thermoplastic sealants, avoid smoothing the joint, for example with a finger, to improve its appearance. Evaporation of the solvents causes the sealant to lose volume, which can cause it to delaminate.

Roof seams protect your home from air and water infiltration and ensure the comfort of your home. For maximum performance and durability, it is best to choose a quality product and ensure that the application is done properly.

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