Guidelines for double-layer pitched roof thermal insulation using URSA® wool

Required tools and materials:
1. Mineral glasswool insulation panels URSA® FKP "Energy saving house"
2. Mineral glasswool insulation felts URSA® DF40 "Warm celling"
3. Mineral glasswool URSA® DF35 "Super house"
4. Mineral glasswool elastic felts URSA® SF40 "Steep roof"
5. Insulation foils URSA® SECO 150
6. Insulation foils URSA® SECO 200
7. Roof membranes URSA® SECO 1000 S
8. Roof membranes URSA® SECO 3000 S
9. Roof membranes URSA® SECO 4000 S
10. Two-sided sticking tape URSA® TOP DK
11. Caulking tape URSA® TOP U
 

Guidelines for double-layer pitched roof thermal insulation using URSA® wool:

URSA® insulation felts: DF40, DF35, SF40

Step 1
Before applying thermal insulation to a pitched roof, the roof structure must be tightly protected against precipitation and wind — preferably, after the roofing has been laid.

Step 2
After unpacking URSA® insulation felts, wait several minutes until the wool expands to its nominal size.

Step 3
Using a sharp tool (e.g. the URSA® knife), on an even plank, cut off a strip of felt. The length of the strip must be equal to the inside distance between the rafters (where the felt is applied) plus 2cm excess necessary to keep the URSA® wool stuck in the space between the rafters and to fill any irregularities tightly.

Step 4
Insulating should begin from the bottom of the rafter, and each consecutive element should be closely butted against the previous one, which helps to avoid heat leakage bridges.

Step 5
To help protect the wool from slipping out, support it with thin, zinc-coated steel wire, stretched between nails driven from the bottom of the rafter (every 60–70cm). Cutting elements of a specific size helps to minimize the amount of wasted wool.

Step 6
When laying wool strips next to the required ventilation void (the recommended height is 2–4cm), it is especially important to leave an air duct. This can be done using delimiting timber battens or zinc-coated steel wire.

Step 7
The other thermal insulation layer is applied across and under the rafters, between timber battens or metal sections fixed to the rafters. The lower thermal insulation layer covers the rafters and reduces thermal bridges. The thickness of URSA®FKP insulation panels or URSA®DF40, DF35, SF40 insulation felts in this layer is 40 or (more often) 50mm.

Step 8
On this thermal insulation, URSA® SECO 150 (200) insulation foil is fitted. It is stapled to timber battens or metal sections using the URSA® TOP-DK double-sided adhesive tape. The approximately 10cm laps between the foil strips are joined with the same tape. The joints of the foil with the rafter plate, gable wall etc. are sealed with the URSA® TOP-U caulking tape and a retaining batten.

URSA® FKP Insulation Panels
The procedure is similar to the one with rolls, except 600 x 1,250mm panels are used for insulation. When installing the second insulation layer, the axial distance between the battens is 40cm.