Boldroll - General Specification

Listed in order of fixing

HANDLING AND STORAGE
Materials should be unloaded as close as possible to the building where they are to be installed. On site, packs should be stored on a firm, dry base away from the possibility of damage. Sheeting packs should be laid on pallets or bearers to allow ground clearance. Bearers at least 100mm x 50mm should be arranged at the same centres under each pack, which must not exceed 2 packs high and must slope sufficiently to allow any rainwater which penetrates to drain away. A tarpaulin should cover the stacks not touching the surface of the sheets, this allows for circulation of air. To prevent damage to the coating on installation, the sheets must be lifted not dragged from the pack. Damage to the surface coating can be repaired with touch up paint. (Supplied by Britmet Tileform Ltd.)

1. EAVES DRIP FLASHING
Supply and fit Britmet Tileform eaves drip flashing. Manufactured and coated in identical material to main roof covering. To be a minimum girth of 140mm, once bent, fixed with secondary fixings and butt jointed. (Manufactured length - 2m)

2. UNDERLAY
Supply and fit Tyvek 2001 B pro breather membrane by Klober or
similar approved. Laid horizontally across purlins, on top of and
flush with the front edge of the Britmet Tileform eaves drip, all to manufacturers instructions.

Note: if the purlin centres are greater than 900mm, lattice support wires should be used to eliminate the sagging of the breather membrane.

3. PURLINS & RAFTERS
Size and centres to be designed to suit Britmet Tileform roofing sheets.

Note: for timber purlins ­ the Tek fastener must have a min. of 38mm penetration. Note: steel & zed purlins ­ should be a min. gauge of 1.25mm.

4. ROOF COVERING
All roof sheets to be manufactured by Britmet Tileform Limited.

All 0.9mm Boldroll galvanised steel sheets are coated using a pigmented mineral filled acrylic coating, available in six standard colours.

Note: All sheets MUST be laid from right to left. Note: the first sheet must be laid so that its left-hand edge is perpendicular to the eave.

All sheets should be laid full length ridge to eaves where possible and securely fixed to the substructure.

Note: where an end/head lap is to be used, for a roof pitch of 10° or more ­ allow a minimum lap of 75mm on the eaves sheet. For a roof pitch of 9° or less ­ allow a minimum lap of 300mm on the eaves sheet.

Lapping requirements: lapping to be undertaken over supported areas only and all sheets must be mitred.

5. FIXINGS
5a Main sheet fixings. To be fixed through the crown of the profile using Tek screws, cap colour to suit.

Fixings to be placed at 2no. per sheet, per purlin, with the exception of the eaves and ridge purlins which shall be placed at 3no.

5b Side lap stitching.

Stitching screws to be placed every third tile for roof pitches of 10° or more. For roof pitches of less than 10°, they should be placed every second tile.

Tek screws supplied by Britmet Tileform Limited. (These quantities may vary due to wind loading or other factors)

Note: for coastal areas, stainless steel Tek screws must be used.

6. FIXING
All holes in the sheet must be drilled (not punched).

All cutting must be made by a 110-volt nibbler or jigsaw, and take place on the ground or away from the material already fixed.

All on site cutting to be immediately treated with Firtan, an anti-corrosive material, or touch up kit, provided by roof sheet manufacturer.

Note: After cutting, all swarf must be removed from the roof immediately.

7. RIDGE / HIP FLASHING
To be manufactured and coated in identical material to main roof covering. Minimum girth of 400mm, five times bent, butt jointed with 50mm understrip or lapped 50mm. (Manufactured length ­ 2m).

Fixings to be placed at 3no. per side.

For roof pitches of 10° or below, hip details should be sealed using compriband expanding foam (B52 25mm x 10mm x 4m).

8. BARGE / MONO RIDGE FLASHING
To be manufactured and coated in identical material to main roof covering. Minimum girth of 340mm, three times bent, butt jointed with 50mm understrip or lapped 50mm.

Manufactured length - 2m

Fixings to be placed at 3no. per side

9. VALLEY FLASHING
To be manufactured and coated in identical material to main roof covering. Minimum girth of 420mm, three times bent, butt jointed with 50mm understrip or lapped 50mm.

Manufactured length ­ 2m

Fixings to be placed at 3no. per side.

For roof pitches of 10° or below, valley details should be sealed using compriband expanding foam (B52 25mm x 10mm x 4m).

10. PIPE FLASHING
All standard vent pipes to be finished with Dektite pipe flashing

(Supplied by Britmet Tileform Ltd.)

11. UPSTAND / APRON FLASHING
Manufactured and coated in identical material to main roof covering. Upstand - minimum girth 350mm, twice bent Apron - minimum

girth 300mm, three times bent Butt jointed with 50mm understrip

or lapped 50mm.

Manufactured length - 2m.

Fixings to be placed at 3no. per side.

12. SPECIAL FLASHING
All chimneys, vents and special flashings, non-standard dimensions. Manufactured and coated in identical material to main roof covering or as required by the client.

13. FLASHING END CAPS
For ridge, barge and hips.

Manufactured and coated in identical material to main roof covering.

14. PLASTIC COMB FILLERS: RIDGE, EAVES, HIP AND VALLEY
For ridge and hip details, to be Tek screwed to the sheet.

For eaves and valley details, to be Tek screwed to flashing.

Supplied by Britmet Tileform Ltd.

Note: for roof void ventilation at the eaves, use either soffit ventilation or the over fascia ventilating system, OFVS supplied by Britmet Tileform Limited.

For duo roof pitches greater than 15° ­ OFVS 10

For duo roof pitches less than 15° ­ OFVS 25

15. SEALANT
All sealant for side laps to be butyl mastic bead, code IDL 0303, grey or black. Pitches greater than 9° ­ minimum mastic bead diameter 6mm Pitches less than 10° ­ minimum mastic bead diameter 10mm

Supplied by Britmet Tileform Limited.

16. COMPLETION
All work to be inspected upon completion and any damaged work to be replaced.

All debris to be completely cleared from the roof area prior to the removal of the scaffolding.