Omegabuild Guide to
building a timber frame Carport or Canopy
A BASIC CARPORT WILL NEED:
1. Polycarbonate sheet, trimmed and taped.
2. Glazing bars to join the sheets.
3. F Section to finish and secure the edges.
4. Fixing buttons to secure larger sheets between the bars.
5. Sheet closure for the bottom edge.
6. Butyl Foilband flashing (polycarbonate compatible) to
seal the top against a wall.
7. Guttering.
CHOOSING YOUR POLYCARBONATE
·
10mm structured polycarbonate is the cheapest material
for an open sided carport or pergola.
·
If you are are building a large structure you could
also consider 16mm or thicker.
·
For a
conservatory, choose the thickest you can afford giving extra insulation.
·
Use the
widest sheet you can comfortably handle, this will reduce the number of glazing
bars required keeping costs down. It is very easy to underestimate the
size and difficulty of handling sheets particularly in windy conditions.
SUPPORT
We recommend rafters at 600mm or 700mm centres depending on the width of
sheet used (maximum width 1830mm or 2100mm). This will support the sheet
on both edges and twice in between. F Section is used to start and finish
the carport and glazing bars used to connect the sheets. Fixing buttons
are used on the support rafters between the glazing bars. Decide which
sheet you would like then check available widths. Ideally we would
suggest your Timber to be at 610mm centres (10mm Clear or bronze haze ( Borg))
or 710mm centres (all other polycarbonate).
CONVENIENT LEAN TO CANOPY KITS
Omegabuild can supply a timber supported lean to kit with the components
you require. It is based on 1050mm sheets and can be supplied with 10 twinwall
,16 triplewall or 25mm polycarbonate sheets.
To see the range of sizes we offer have a look on our website
If you would prefer to not use timber rafters we also have a range of
self supported lean to roof kits. To
find out more have a look on our website
If you would like to have a
complete aluminium kit with legs and guttering Omega offers their Smart canopy
and carport system. To find out more have a look at our website
REPLACING CORRUGATED SHEETS
PVCu corrugated sheets are normally fixed to purlins. Screw down bars do
not work on purlins. Though not recommended by manufacturers, snap down
bars can be used to cross purlins, Timber rafters would be better, then any bar
can be used and with more fixings. The important point here is the number of
fixings points holding your roof down. E.g. a 3m projection with purlins
may only have 4 fixings points per bar, imagine a sudden gust of wind
underneath that. Better too many fixings than not enough.
PITCH
The manufacturers minimum recommended pitch is 5°, to cover adequate
drainage , this is a fall of 265mm over 3000mm. This is a minimum , we would
recommend a fall of 500mm.
TAPE
Both ends of the polycarbonate sheet should be taped to stop dust and
insects entering the flutes. Breather tape should be used at the bottom
allowing air as it expands and contracts to exit and enter the flutes. Omegabuild
can supply the sheets trimmed and taped.
G L O S S A R Y
Rafter
A roof supporting beam that runs from top to bottom down the slope.
Purlin
A roof supporting beam that runs horizontally, sometimes supporting rafters or
running between them.
Glazing bar
Joins two sheets of polycarbonate together.
Self supporting
Acts as a rafter as well, needing no additional support.
Timber supported
Needs to sit on a timber support.
A roof supporting beam that runs from top to bottom down the slope.
Purlin
A roof supporting beam that runs horizontally, sometimes supporting rafters or
running between them.
Glazing bar
Joins two sheets of polycarbonate together.
Self supporting
Acts as a rafter as well, needing no additional support.
Timber supported
Needs to sit on a timber support.
The Snap
down bar has an aluminium base which is screwed onto the timber and has a
plastic snap on capping Although it is not recommended this bar can be used
crossing purlins particularly when replacing corrugated sheet. Please ensure
you check the Omegabuild fitting guides for the maximum distances allowed
between cross purlins. If in doubt place timber noggins between the cross
purlins to create a virtual rafter.
The Screw down aluminium bar has a rubber
base and can only be used on a complete rafter. The capping is all aluminium with
an aluminium screw cover cap and it is
screwed into the rafter. This is the stronger and more professional method
suitable for all thickness’s of polycarbonate and even single glazed glass.
Edge bar
A bar used on the sides to finish off with polycarbonate on one side only.
Sometimes an adapted main bar and not always available from every manufacturer.
Upvc Edge trim /F section
Converts a main snap down bar into an edge bar.
F section
Used instead of an edge bar. Useful with its leg that can be used down or up if against a wall. Plastic or aluminium depending on thickness.
Breather tape
Put on the bottom of the sheet allowing air in and out of the flutes as it expands and contracts while keeping dust and insects out.
Sheet Closure
Plastic U section with a drip that protects the breather tape and stops water running up the underside of the sheet.
Edge bar
A bar used on the sides to finish off with polycarbonate on one side only.
Sometimes an adapted main bar and not always available from every manufacturer.
Upvc Edge trim /F section
Converts a main snap down bar into an edge bar.
F section
Used instead of an edge bar. Useful with its leg that can be used down or up if against a wall. Plastic or aluminium depending on thickness.
Breather tape
Put on the bottom of the sheet allowing air in and out of the flutes as it expands and contracts while keeping dust and insects out.
Sheet Closure
Plastic U section with a drip that protects the breather tape and stops water running up the underside of the sheet.
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