HOW TO CALCULATE YOUR ROOF SIZE!
Struggling to know how many slates you need for your project?
Why not let us do the work? Simply use our calculator or send us your dimensions and we’ll calculate how many slates you need.
Struggling to know how many slates you need for your project?
Why not let us do the work? Simply use our calculator or send us your dimensions and we’ll calculate how many slates you need.
If your property has hips and valley, like in the picture above, please get in contact so we can help you accurately calculate your roof size. On condition that your roof is a simple up and over, like the picture below, you can calculate it yourself.
Start by measuring the length of your building. Followed by the length of the ridge or, if you can not get access to your ridge, measure the width of the property instead (call us if this is the case). In this example the Length is 8 metres (800cm) and the ridge length is 4 metres (400cm). Simply multiply this figure together to get a square meterage of one side of your roof. In this case 8 x 4 =32Sqm as the roof has two sides simply multiple this figure by 2, 32 x 2 =64 Sqm is the total size of your roof.
To then calculate how many slates you will need simply check out our Slates sizes and Quantity Guide. You will ned to multiply your Sqm2 by the amount of slates per sqm2. For example if your roof is 64Sqm2 and you want to use 500x250mm slates then you would multiply 64 x 21 = 1,344 slates. Please note this doesn’t take in to consideration of skylights, chimney breasts, hips or Valleys which all will add to the quantity of slates needed. As they will need to be cut, we ALWAYS recommend adding a 10% wastage amount to your order to make sure you don’t run out.
If you want to make your life easier simply use our SLATE CALCULATOR TOOL
Our calculator will automatically work out the amount of slates, slate and halves and ridge tiles you will need specifically based on your location. It will recommend what size slate you can use and will give you the option to choose what size and what slate you prefer from our shop. Once in checkout, it will also calculate your delivery costs to your door.
Dependant on where you are in the UK and the pitch of your roof, you may be limited to legally installing specific sized slates and using a specific headlap. Our calculator will automatically work this out and will show you what’s available tailored for you. It will show you all the results once you have filled in the simple form.
Not only do you need to work out how many slates and slate and halves you need. You also need to consider the ridge caps, Our calculator will automatically work out how many you will need and will add it to your order. Check out our selection HERE
Slate and halves are literally a full sized slate with half added on. For example a 500x250mm slate would use a 500x375mm slate and half. Slate and half are crucial as you will need one per row of slates. They offsets the slate pattern across the roof. Our Calculator will automatically work out how many you will need and will add it to your order..
Once the calculator has determined how many slates you need, you can scroll through the sizes that are available to you. There is a (recommended- most common) TAB next to the slate size we would highly recommend for your project. Once your happy with the size, simply scroll through your choice of slates in that size, once you have chosen the slate, it will automatically add them as well as the correct slate and halves and ridge tiles to your basket, helping to make ordering super easy.
It’s essential to know what the Pitch of your roof is, check out this guide if you need help.
more infoLiso Slates
Ferlosa Slates
Lousaval cafersa LV11 & LV15
British Slates
Here is our terms and conditions.
Check out our Youtube channel HERE to see projects.
Stuck on how many slates you need? why not try out our slate calculator