Alliance Roofing guidance · Updated November 2, 2026
More insulation or more ventilation?
Start by understanding the existing assembly and moisture path. Examine indoor air leakage, ducts exhausting into the attic and obstructed air inlets. A compact roof and a ventilated attic need different approaches. Adding a vent without diagnosis can leave the cause unresolved.
What does R-value mean?
R-value expresses thermal resistance. Compare the insulation rating, thickness, continuity and thermal bridges. A panel’s advertised rating is not automatically the rating of the whole roof. Building needs and applicable requirements determine the design.
Condensation, mould or a roof leak?
Record whether marks appear during rain, thaw, cold weather or high indoor humidity. A ceiling stain does not necessarily locate the entry point. Have the covering, penetrations and accessible attic examined. Visible mould also requires investigation of the moisture source; covering it does not fix the problem.
Cathedral roof, interior insulation or inverted roof?
These arrangements require analysis of the layers and their drying potential. In an inverted roof, insulation is above the waterproofing. In a cathedral roof, available space limits the work. Before cavities are closed, clarify air and vapour control, connections and the ventilation strategy where required.
Prepare your request
Provide the address, roof type, symptom and when it appeared. Add available documents and safely taken photographs. We will confirm the intervention scope and availability.
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