Important
Considerations
Polycarbonate
is both versatile and tough. Use it in place of
wired glass and corrugated roofing sheets. Its
light transmission, insulation and strength are
essential properties for modern conservatories.
The ideal conservatory roofing sheet-use also
for glazing and insulation on greenhouses, porches
and carports or roofing sheds and workshops. Also
suitable for insulated cloches and cold frames.
Know
Your Roofing Sheets
Most
makes of multiwall roofing sheet have a greater
thickness in the top wall. This top wall surface
normally consists of a co-extruded outer layer
of UV absorber that forms a barrier against
UV degradation. The protective film on the sheet
will indicate this surface and sheets must always
be installed with this surface outwards/external.
Roofing
sheets will expand and contract as the temperature
changes - up to 4mm per metre, in both directions,
between mid-winter and high summer. Dark materials
expand faster. Allowance must be made for this
when fitting. Always lay roofing sheets with
the flutes running from the top to the bottom.
Snow
Loading
The
width of sheeting and spacing of glazing bars
must always allow for adverse weather conditions.
The weight of the snow load in the area of installation
is established by national and regional standards.
If in doubt, check with your supplier.
Using
Polycarbonate Sheeting with Kents Glazing
Bar Systems
Kent's
glazing bars that are fitted down the long edges
of each sheet, are designed to allow for expansion.
Fix the sheet at one end to allow this movement
to take place in a controlled manner.
Seal
the flutes of the sheet at the top end with
aluminium tape. The bottom end should be finished
with ventilated breather tape and covered by
the a sheet closure.
Sheets
can be fitted vertically, but are normally used
for roofs with a minimum pitch of 10 degrees.
The
majority of sheets are used at a width of 1050mm.
The maximum width depends on the supporting
structure. If no cross supports are used then
fix 10mm sheets up to 700mm and 16mm sheets
up to 1050mm. Where the snow loading is not
greater than 60kg/sqm. Please check with us.
10mm
sheets glazed at 1050mm wide need support across
with width(purlins), at intervals of 1500mm.
Wider sheets will need additional supports.
Kent's
glazing bars do not require additional mechanical
fixings except where extreme weather conditions
are encountered, when the use of a button fixing
centrally positioned on to a support in the
middle of each sheet is recommended.
Any
trimming of the sheets may create swarf in the
flutes, which must be removed. This is best
dome with a suction type (vacuum) cleaner. Avoid
getting moisture in the flutes, at any time.
Leave
the protective film on the sheets until installation
is complete, folding back only where necessary
to expose areas to be covered by the glazing
bars, silicone sealant and flashing. This film
should then be removed as soon as possible and
it is therefore advisable to advance construction
of the roof as far as possible before fitting
glazing sheets.
Silicones,
Flashing & Cleaning
Although
polycarbonate is extremely tough and hard wearing,
it can be affected by chemical agents. Care
must be taken in the choice and use of such
items as silicon sealants and flashing which
will be in contact with the sheet.
Ploycarbonate
sheets should only be cleaned with water and
mild detergent, applied with a soft cloth. Never
use solvents to remove marks, although paint,
whilst still wet, may be removed with white
spirit, provided all excess spirit is cleaned
off and thoroughly washed down with water. If
in doubt-check it out!
Should there be any doubt about the compatibility
of any material, check with us.
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