Why Surveyors Flag Spray Foam Insulation
(And How to Fix It)
The Survey Report Shock
Your buyer's mortgage surveyor has flagged spray foam insulation as a significant issue, potentially recommending mortgage refusal. This isn't surveyors being overly cautious—they're following strict industry guidelines.
What Surveyors Say in Their Reports
Typical survey language regarding spray foam:
"Spray foam insulation has been applied to the underside of the roof covering. This prevents inspection of the roof timbers and may affect ventilation. We recommend further investigation by a specialist and advise the lender that this may affect mortgageability."
"Spray foam insulation noted. Unable to inspect timber condition. Retention recommended until foam removed and timber inspected by qualified surveyor."
"Spray foam present. Property may not meet lending criteria. Recommend buyer seeks alternative property or negotiates foam removal prior to completion."
Why Surveyors Flag It
1. Professional Liability
Surveyors carry professional indemnity insurance. If they miss structural problems hidden by foam, they're personally liable for damages.
Their position: "I can't see the timber, so I can't confirm it's sound. I must flag this to the lender."
2. RICS Guidance
The Royal Institution of Chartered Surveyors (RICS) has issued specific guidance on spray foam. Surveyors must follow these standards or risk professional sanctions.
RICS stance: Spray foam prevents proper inspection and should be flagged as potentially affecting value and mortgageability.
3. Lender Instructions
Mortgage lenders explicitly instruct surveyors to flag spray foam. Surveyors who don't report it can lose lender panel membership.
Instructions typically state: "Report any spray foam insulation. Recommend retention or rejection if present."
4. Hidden Damage Risk
Surveyors have seen cases where foam hid severe rot, decay, or structural failure discovered only after removal. They can't risk recommending a property that may have hidden problems.
Worst case scenario: Buyer purchases, roof fails within 5 years, surveyor sued for missing obvious risk.
5. Ventilation Concerns
Spray foam typically blocks roof ventilation required by UK building regulations. Surveyors must note regulatory non-compliance.
Building regs issue: Property may technically not comply with Part C (moisture control) of building regulations.
Types of Survey Ratings for Spray Foam
Condition Rating 3 (Most Common)
Meaning: "Defects that are serious and/or need to be repaired, replaced or investigated urgently."
Most surveyors assign spray foam a "3" rating, the highest severity level.
Lender response: Typically mortgage refusal or major retention (holding back funds until resolved).
Condition Rating 2 (Less Common)
Meaning: "Defects that need repairing or replacing but are not considered to be either serious or urgent."
Some surveyors use "2" rating if foam appears professionally installed with no obvious issues.
Lender response: May still refuse mortgage depending on lender policy.
Can You Challenge the Surveyor's Report?
Short answer: No, not effectively.
Surveyors flag spray foam based on industry standards and lender instructions. Challenging their professional judgment rarely succeeds because:
- • They're following RICS guidance (can't go against professional body)
- • Lender instructed them to report foam (they must follow lender requirements)
- • They physically cannot inspect timber (legitimate professional concern)
- • Challenging costs time/money while buyer's mortgage clock ticks
Even if you "win" the challenge, the lender will likely still reject the mortgage based on their own policy.
What Happens After Surveyor Flags It
Typical sequence of events:
- Day 1: Survey conducted, foam discovered
- Day 3-5: Survey report issued to lender with spray foam flagged
- Day 7-10: Lender reviews report, consults underwriting policy
- Day 10-14: Lender rejects mortgage application citing spray foam
- Day 15: Buyer receives rejection, informs seller/estate agent
- Day 16-20: Buyer decides whether to proceed as cash buyer or withdraw
- Day 21: Sale falls through (most common outcome)
How to Fix It: The Only Solution
To satisfy surveyors and lenders, you must:
Remove ALL spray foam using manual methods
Professional removal by specialists using hand tools only
Obtain professional certification
From RICS or PCA qualified surveyor confirming complete removal and timber soundness
Repair any timber damage discovered
Professional repairs with guarantees
Provide documentation to buyer's lender
Certificate, photos, repair invoices before new survey
What Won't Work
- ✗Getting a second survey opinion—result will be same
- ✗Providing installer's certificate—lenders don't accept these
- ✗Arguing foam was "professionally installed"—doesn't matter to lenders
- ✗Offering indemnity insurance—lenders won't accept it for spray foam
- ✗Hoping buyer finds different lender—99% chance same result
The Bottom Line
Surveyors flag spray foam because they're required to by professional standards, lender instructions, and liability concerns. This isn't negotiable or challengeable.
The only way to get a survey report that doesn't flag spray foam is to have no spray foam—which means professional removal and certification.
Remove it, certify it, and your next survey will be clean.