Told to remove it, or holding a removal quote
About to remove foam bonded to the slates, but the covering needed checking first
Fylde coast · Recent inspection · Spray Foam Inspection
The house
Detached 1932 house, extended to the rear, under natural slate; no underlay seen. Three connected lofts, two of them half-hipped. Boarded soffits; no soffit, ridge or gable vents seen.
The foam
Closed-cell foam, completed in 2020, bonded straight to the slates; the installer's order form had 'Spray to Felt' ticked No. Eaves packed solid along the runs reached; floor insulation still in place, some still bagged.
The paperwork
Held: order form, pre-contract email, a thirty-year warranty and its terms. Not provided: the inspection report the warranty says the installers would carry out, a signed completion note and any product data, so the product cannot be identified.
Why they called
The owner intended to have the foam removed and wanted an independent record first; the roof had not been inspected since it went in.
What was measured
- 23 timber readings, 11.6% to 20.5%. The 20.5% was on a rafter in a hip corner beside a purlin, next to blocked eaves.
- Air 13.3 to 13.8 g/kg at three main-loft points and up to 14.3 g/kg in the second section: generally wetter further from the hatch.
- Foam specified at about 50 mm on the order form; depth not measured.
What it means
Most of the evidence fits condensation: wetter timber in closed-in corners beside blocked eaves, generally wetter air further from the hatch. But in one area there were pale mineral deposits behind the foam, water marks along a purlin, and broken foam with slate showing through. Such deposits are, in the inspector's view, typically left by water running through and drying out, not by condensation alone. So water coming in through the slates could not be ruled out, and if it is, removal would not stop it.
What happened next
A roofer to check the covering from outside first, above the deposits. The owner's solicitor to ask the installer for the missing documents. Then decide about the foam; if it comes out, record the timber behind it while visible.
For other homeowners
Planning removal? Check the covering is sound first. Taking foam off a roof that lets water in spends the money and leaves water landing on bare timber.
Read the guide: Do you need to remove spray foam? Removal, costs and what to check first · Spray foam cold calls and removal scams: how to check a caller
The honest limit
Almost all the timber is behind the foam, so the 23 readings cover only what a meter reached. No outside air or surface readings were taken, the covering was seen from the ground, and one lower slope was not reached.