Loft Insulation

---

What Is SuperFOIL Insulation?

SuperFOIL is a layered reflective insulation (multifoil); it typically combines layers of reflective foil and insulating wadding. 

It often acts as a 3-in-1 product: thermal insulation, vapour control layer (VCL), and a radiant barrier. 

Because of its design, it can achieve decent thermal resistance (R-value) without being super thick. 

It’s quite lightweight and relatively easy to install (cuts with knife/scissors). 

Some SuperFOIL products are made with a high recycled content and are recyclable. 

Pros & Benefits for a Loft

Advantages:

1. Space-saving: Because of its slim profile, it’s good where you don’t want or can’t have very thick insulation.

2. Radiant barrier: Reflects radiant heat, which can help in both summer (reflecting heat out) and winter (reducing heat loss).

3. Moisture control: The built-in vapour control layer helps reduce condensation risks if installed correctly. 

4. Versatility: Can be used in walls, roofs, floors  one product for several uses. 

5. Durability: Long lifespan (SuperFOIL claims 50+ years) and stable performance.

Ventilation:

1. Air gaps needed: To work effectively, multifoil insulation generally needs air spaces (on one or both sides) to reflect heat properly. 

2. Condensation risk: If you block ventilated spaces or install it incorrectly, moisture could build up. As some DIYers point out:

3. Performance vs traditional insulation: Some argue that after you account for required air gaps, multifoil may end up being comparable in thickness to PIR or mineral wool. 

4. Delicate installation: Foil products can tear or get damaged, so care is required when stapling/taping.

5. Cost: Depending on the variant, it can be more expensive per m² compared to basic loft insulation (though it depends on what you're comparing to).

How to Use SuperFOIL in a Loft

Here are a few common ways people use it in lofts:

Under the rafters: Installing SuperFOIL on the underside of the roof (i.e., between/below rafters) but must maintain ventilation per building regs.

On the loft floor: Some use SuperFOIL above or below loft boards. But if used under floorboards, it needs proper sealing and possibly additional insulation.

Hybrid system: Combine with traditional insulation (e.g., mineral wool); use SuperFOIL as a top layer or as a vapour barrier/radiant layer.

Installation tips:

Leave recommended air gaps (check the datasheet for the specific SuperFOIL product).

Use foil tape to seal joints.

If using as VCL, ensure continuity and proper overlap.

Make sure roof ventilation isn’t blocked.