Roofers perform more than just the old “find the hole and fill it” before applying sealant. The sealant only works if it is properly applied to an appropriate surface under real-world assumptions about how that roof will move over time.
1: The actual leak
Water does not always drip where it penetrates. A roofing contractor will identify probable trouble spots (flashings, joints, valleys, penetrations, and upstands) and examine for broken seams or lifted edges, cracks, or inadequate repair screws.
2: Surface preparation
The new sealant will not stick to dirt, moss, chalking coatings, loose bitumen, or old flaking paint. A typical case requires some cleaning, drying, and if necessary, abrasion or priming of a surface. They will also assess if there is old sealant, and whether it can stay or needs to be removed. For Roof sealant, contact www.ct1.com/product-applications/ct1-the-ultimate-roof-sealant
3: Moisture levels
A roofer will investigate potential damp within the build-up (soft spots on flat roofs, blistering, staining, and mould) as well as seeing if the substrate is dry enough for their chosen product. Many sealants will allow for a little bit of moisture, but others won’t.
4: Movement and detailing
Temperatures cause roofs to expand and contract. This means that the joints, trims, and penetrations move the most. A roofer may recommend a flexible sealant, or strengthening by means of tape, patching compound, or newly-fabricated flashing to prevent recurrence.
5: Substrate compatibility
Material-specific products and primers are required for different roofing materials. This may result in bad adhesion or chemical reactions when using the wrong sealant.
As long as it’s done properly, sealant is a good fix.
