Decking calculator
Work out the boards, joists, posts and screws for a deck. Enter the size and board width and get the full list.
Work out your decking
Enter the deck size and choose a board width.
decking boards, 3.6m, wastage included
Otis pulls boards, joists, posts and fixings as one job and prices them on your live stock.
Assumes 3.6m boards with a 5mm gap, a support post about every 1.5m, and around 40 screws a square metre. An estimate, always confirm with your merchant.
How the numbers work
The calculator works out the deck area, then the number of 3.6m boards needed to cover it including a gap between boards and a wastage allowance. Joist timber is estimated from your joist spacing across the length of the deck.
Support posts and screws are estimated from the area. It is a solid starting point for ordering, but a merchant running Otis can confirm every line on live stock.
This is what Otis does, instantly
A calculator works out quantities. Otis takes a customer question, works out the materials, checks live stock and pricing in the merchant’s own system, builds the quote and takes the order, day or night.
Common questions
How many decking boards do I need?
Divide the deck area by the coverage of one board, allowing for the gap between boards and some wastage. This tool does that for standard 3.6m boards.
What joist spacing should I use?
400mm centres is common for softwood decking and gives a firmer feel. 600mm may be acceptable for some composite boards, so check the board maker guidance.
Should I add wastage?
Yes. A 10 percent allowance covers cuts, the pattern you lay and the odd reject board.
Does this include the frame and posts?
It estimates joist timber and support posts. Ground conditions vary, so confirm the substructure with your merchant or a builder.
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See Otis quote the whole deck
From posts to boards, Otis prices the full list on your live stock in seconds.