What should be the parameters of the lathing for polycarbonate?

Question

Hello! We decided to attach a veranda to the country house. As planned - the roof should be made of polycarbonate. But then the question arose with the crate. After all, a polycarbonate roof should be as transparent as possible, do you need a crate when installing such a roof? (October 21, 2013, Arseny)

Answer

Hello. Yes, you are right, a polycarbonate roof has a certain set of obligations:

The lighting level in a room with a polycarbonate roof must not be lower than the established standards;
A polycarbonate roof should let in sunlight, but soften its brightness.
The polycarbonate roof must be equipped with a ventilation system;
When installing a polycarbonate roof, all building codes for the strength of the roof frame and roof must be observed, as well as the indicators of heat, hydro and noise insulation.

A competent rafter system and crate can provide all this. As with the choice of any other roofing material, the step of the crate depends on the slope of the roof. If a flatter roof is designed, the stronger the crate should be. The minimum allowable slope of the polycarbonate roof is an angle of inclination of 30 degrees. The optimal angle is considered to be 50 degrees.

In addition, you must also take into account possible snow loads. The more snow, the smaller the step of the crate.

Based on these options, if you plan the roof of the veranda is made of polycarbonate, then choose a steeper roof structure, and preferably arched. The arched shape of the roof is able to withstand maximum loads.

In order to do without a crate at all, the arch should be made of sheet polycarbonate with a thickness of 16 mm. the rafter pitch should be maintained at 2 m 30 cm, and the radius of curvature should be the same. The crate in this case is done only at the joints of the supports.

When installing a pitched roof, the step of the rafters should be equal to the width of the sheet. After all, just on the supports and the sheet will be attached.

Often when calculating the step of the crate, the following principle is used: The width of the step of the crate should be equivalent to the thickness of the polycarbonate sheet. The thickness is 4 mm, then the lathing pitch is 40 cm, 6 mm is 60 cm, etc.

It is worth noting that polycarbonate sheets need to be fastened so that the stiffeners of the roofing material are perpendicular to the crate (strictly at a right angle).

Therefore, to make the design look most airy and transparent, it is worth using polycarbonate with the greatest thickness. In this case, however, you have to spend money. As a rule, such polycarbonate is much more expensive.