The deciding question: is it dry?
Moisture trapped in foam or under old roofing is the main reason a recoat won't work. A coating over wet foam blisters and fails. An inspection checks for soft spots and moisture before any recommendation is made.
Recoat when
- The foam is firm and dry
- Damage is limited to the coating and small areas
- Drainage is good, or low spots can be fixed with foam
Re-foam when
- The foam has eroded or lost thickness
- The roof has many low spots or poor slope
- The roof is mostly dry but in rough shape
Tear off when
- Large areas are wet
- The deck underneath is damaged or rotted
- There are too many layers already
Costs compared
A recoat costs a fraction of re-foaming, and re-foaming typically costs less than a full tear-off and new roof. See Placitas roof coating prices.
Call (505) 588-5928 for an honest assessment.
Common questions
Can foam go over an old tar and gravel roof?
Often, after loose gravel and wet areas are removed, if the roof is mostly dry.
How do you test for moisture?
By probing the foam, checking for soft spots and, when needed, cutting small test areas.