Reroofing Over Full-Coverage Ice and Water Shield
Bulletin dated: September 28, 2026
When an existing full-coverage membrane cannot be removed, TAMKO requires its specified synthetic underlayment over the retained membrane. The notice also requires deck inspection, assessment of moisture and irregularities, and suitable nail penetration through all layers
TAMKO technical bulletin: Requirements for Installing Shingles Over Existing Full-Coverage Ice and Water Shield.
What this means for your roof
When an existing full-coverage membrane cannot be removed, TAMKO requires its specified synthetic underlayment over the retained membrane. The notice also requires deck inspection, assessment of moisture and irregularities, and suitable nail penetration through all layers. It limits the existing ice-and-water-shield layers and does not allow concealed deck problems to be ignored.
A useful question for your contractor
Ask for the retained-layer count, deck and moisture findings, specified synthetic underlayment and fastener plan in the written scope.
Ask for the answer to be tied to the actual roof condition and the exact product being installed. Keep the agreed repair or installation detail with your estimate and project photos.
Bulletin dated: September 28, 2026. The date shown identifies the manufacturer document used for this summary.
Read TAMKO: Requirements for Installing Shingles Over Existing Full-Coverage Ice and Water Shield
This homeowner summary explains the cited bulletin. The complete manufacturer document and current product instructions govern the installation details. A requirement for one manufacturer or product should not be transferred to another without checking.