How Much Material Do I Need For My GRP Roof?

It goes without saying that smaller roofs will need less of our materials while larger roofs will need more, calculating this precisely yourself however may prove difficult. This is why we have produced a table that will help you calculate how much of each material you will need, how much it will weigh and the cheapest combination of products you can buy to fulfil your requirements. Measuring your square/rectangle roof is simple, select a corner and measure along on end of it, and then the other.

If your roof is in an L sort of shape, then all you need to do is measure along both of the ends of long corner as if it was a square and then find out the length of the parts of the roof the make of the L indent and multiply them to get the area of the smaller section, and then subtract that from the total you had in the first place

 

How to calculate size of a flat roof

The table below will give you a guide for quantities to order depending on the measured roof size.

As you can see, 1.5kg of resin will cover one square metre, while that same area can be covered by just 0.5kg of topcoat. If you are using 600gsm matting as opposed to 450gsm, your resin usage will be approximately 33% higher as the mat is thicker.

GRP roofing table of required materials

Items you will need