Decking calculator
Free tool
Put in the size of your deck and we'll work out every board, joist, post and screw you need, with today's prices. It's the same way our team works it out at the counter in Newcastle.
Your deck
What you need
| Qty | Item | Price |
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Includes 10% extra for cuts and waste. Joists at 400mm centres. Quantities are a guide, so if your deck has steps, corners or an odd shape, call or call in and we'll check it with you.
How we work it out
What's in your list
4.8m reversible boards, 140mm x 28mm, pressure treated. Each board covers about 145mm with a 5mm gap for drainage.
Laid across the boards at 400mm centres, with a frame all the way round and noggins every 1.2m to keep it stiff. 4x2 for ground level, 6x2 for raised decks.
Raised decks only. 4x4 posts every 1.2m each way under the frame, 1.8m long so there's plenty to go into the ground.
Two 60mm decking screws per board at every joist, joist hangers for the inner joists, and wall fixers every 600mm if it goes against the house.
Tips from the yard
Before you start
Measure the length the boards will run and the width out from the house. If one side is longer, use the longer one.
Leave about 5mm between boards so rain can drain and the timber can move.
Give the deck a slight slope away from the house so water runs off.
Brush end grain preserver on any cut ends so they last as long as the rest of the board.
Questions
Decking FAQs
How many decking boards do I need per square metre?
With 140mm boards and a 5mm gap, one square metre takes about 6.9 metres of board, so roughly one and a half 4.8m boards. Put your size in the calculator above and it works out the exact number including 10% for cuts.
How far apart should decking joists be?
We recommend 400mm centres for our 28mm timber decking. It keeps the deck solid underfoot and stops the boards from bouncing.
What size joists do I need?
For a ground level deck, 4x2 (100mm x 44mm) pressure treated joists are plenty. For a raised deck on posts, go up to 6x2 (150mm x 44mm).
How far apart should the posts be?
For a raised deck we put 4x4 posts every 1.2m each way. The calculator adds them automatically when you pick Raised.
Do you deliver decking?
Yes, we deliver timber and decking across Wicklow, Dublin, Wexford, Kildare, Meath, Carlow and Kilkenny. The delivery charge is shown at checkout, or you can collect from our yard in Newcastle, Co. Wicklow.
Not sure about your measurements?
Send us a sketch or call in to the yard and we'll go through it with you.