Open-Cell vs Closed-Cell Spray Foam: Why It Matters

Open-cell and closed-cell spray foam create different concerns for homeowners, surveyors and lenders. Learn why the foam type matters. Spray foam comes in two main forms. Both can be installed safely in some conditions and badly in others. The type affects how lenders, surveyors and homeowners view the situation. ## Open-cell foam – simple explanation Softer, lower density, more vapour-permeable.

Sometimes considered lower risk for moisture but raises its own concerns depending on installation. ## Closed-cell foam – simple explanation Denser, more rigid, less vapour-permeable. Can act as a vapour barrier, which raises moisture management questions if applied without ventilation strategy. ## Why roof inspection and ventilation matter Both types can prevent timber inspection.

Closed-cell, in particular, can change how moisture moves through the roof structure. ## Why foam type may affect survey or lender attitude Lenders may treat the two types differently. Surveyors will often want to know which has been used. ## Why homeowners should not guess Identifying the type from a photo alone is difficult.

Where possible, original installer paperwork is the most reliable indicator. ## Photos that help identify the issue Close-ups, depth references, and shots of the foam at the eaves and ridge. ## Want us to review your spray foam issue remotely? [Start Remote Spray Foam Review](/spray-foam-insulation-help) --- ### What to do next If you are dealing with spray foam insulation in your loft, or thinking about removal, EvoHome Improvements can help you understand the situation calmly and plan the right next step.

EvoHome is an independent home-improvement coordination consultancy and does not carry out the works directly, but coordinates the process and, where appropriate, connects you with suitable independent installers or specialists. Start here: [/start](/start). You can also read more about how this service works at [/services/spray-foam-insulation-help](/services/spray-foam-insulation-help).