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General specification to be used in conjunction with Britmet Tileform 0.9mm
Pantile 2000 roofing sheets.
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 Pantile 2000 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 3no. per sheet, per purlin, with the exception of the
eaves and ridge purlins which shall be placed at 4no.
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.
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