Order an UnderDeck Kit

Deck Depth

Deck depth is the end to end length of your deck joists (see picture to left). Deck joists are the boards that hold the deck boards in place.

When measuring your deck depth, round up to, but not past, the nearest foot. You do not need to measure the width of the ledger board (the board attached to your house) and the header board (the board parallel and furthest from your house) that hold the deck joists in place.

If your have deck joists that are of two or more differing lengths, you can use the length of the longest joist if the joists are within a couple of feet of each other. If you have joists whose lengths are more than a couple of feet different, you can use our simple estimating instructions for your deck and order individual components (it really is simple to manually estimate).

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Deck Width

Deck width is the end to end length of the deck that is perpedicular to your joists (see picture to left).

When measuring your deck width, include the width of the two most outer boards (these are often called edge or rim joists).

If your deck has double joists (two joists that are connected side by side with lag bolts or screws), please specify in the order notes the number of double joists that your deck has and we will contact you with an updated quote.

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Joist Spacing

Joist spacing is the 'on-center' distance from one deck joist to another deck joist. 'On-center' means that you measure from the middle of one joist to the middle of the other joist.

Typical joist spacings are 12, 16 and 24 inches on-center.

If you have 1 or 2 joist spaces that are shorter than the rest that is OK. For example, if you have (13) joist spaces that are 16" on-center and (2) that are 10" on-center, you would use the 16" on-center measurement.

All UnderDeck compenents are designed to be cut. When installing, you cut the collector panels and gutters to size for a perfect fit.

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