We were recently asked how SFUF stacked up against a typical Polyethylene DPC. The first difference is that SFUF is a reflective insulation while DPC is not; it’s a damp proof membrane.
SFUF contains layers of high performance laminated foil materials. In particular SFUF includes two layers of SFTV, SuperFOILs high performance fully woven foil material which is both waterproof, water vapour (VCL) and CE certified.
Our technicians compared performance testing to EN standards for both products and found that the materials in SFUF are as waterproof as any typical PE DPM.
SFTV is W1 waterproof (which is the high standard of waterproofing). A 1200 gauge PE DPS is also W1 waterproof. You may see products that are labelled waterproof, but if they are not labelled W1 then they may be W2 or even W3 a lower performance. A W2 or W3 labelled product may only be considered shower proof or waterproof when protected (e.g. like a material that can be used only in the cavity of a cavity wall).
W1 is the standard needed for use on a roof as it will withstand driving rain, if a material is not stated as being able to be used on roofs it may be W2 or W3.
What about water vapour permeability?
The laminated fully woven aluminium foils that make up SFTV are also impermeable to water vapour, Polyethylene DPCs are not. PE is basically similar to material as a regular sandwich or freezer bag, just much thicker in a DPC.
PE does not create a barrier like a layer of aluminium metal can and with PE osmosis will occur. Where there is water pressure differential water will “pass” which is why DPCs are only used to tackle capillary action damp and they are not used where there is standing water.
SFTV is a fully woven construction, it’s much stronger than Polyethylene and does not stretch like a PE material. SFUF has the benefit that it has not 1 but 2 layers of SFTV and there are protective layers of foam and secondary thinner foil layers that provide additional performance protection. The SFTV material in SFUF has comparable performance to typical 1200 gauge PE DPMs
SFTV has passed the same European Standard as a DPC; EN1928 (the standard of waterproof performance) and is W1 waterproof. In EN standard testing SFTV is superior in strength and vapour control.
We hope this little article helps you appreciate how SFUF makes your important construction projects better.