How Far Can Composite Decking Overhang?

M. John
overhanging composite deck

Overhanging composite decking is vital when it comes to decking buildings. The overhang helps the decking to last for several years; it also helps in enhancing the look of the composite decking.  If you aim to install ultradecking composite in your home, you should allow for sufficient overhanging of the decking. How far can composite decking overhang?

composite deck overhang

 How Far a Composite Decking Can Overhang

Overhanging a composite board is essential if you want it to last for a long time. It is also important if you want the decking to look great. However, the overhang requirements may vary according to the decking manufacturer. Some decking builders leave about one inch of overhang while installing the deckings.

But there are boundaries to how far you can overhang a composite decking. You will want to overhang the decking in the right and most suitable way. When installing a wood-plastic composite, always remember to follow guidelines on how far you can overhang the decking. Composite deck makers considered  1 ½  inch as the ideal measurement for overhanging the decking. If you want to overhang a standard composite board of 5.5 inches, the overhang should be 1 ¾ inch.

You should also ensure that while installing the composite decking, do not overhang the board edge more than one-third of the composite decking material. If you intend to add fascia boards to the composite decking, you should overhang the wood-plastic decking before the fascia. Before attaching the fascia board to the decking, overhang the decking by one ¾ to 2 ¾.

Why You Should Overhang Composite Decking

Overhanging composite decking has a lot of benefits than limitations. Here are a few reasons why you should overhang your composite decking.

 It Improves the Deckings Appearance 

Firstly, Overhanging composite decking can enhance the look of the wood-plastic board. The decking will look more attractive compared to when it’s not overhung.  Overhanging hides all imperfections and makes the deck appealing to the eye. If you are the kind that values aesthetics, overhanging the composite board is essential.

It Enhances the Fascia Board

Secondly, Overhanging makes the fascia board consistent with the composite decking. The fascia edges can look uneven to an onlooker, overhanging the composite decking to improve the appearance. It also enhances the fascia board by covering the uneven edges, thereby making it look attractive.

It Keeps the Joist from Moisture 

Thirdly, Overhanging composite decking keeps the joist from dampness.  It keeps water from the joist preventing it from being trapped under the decking. Overhanging the composite stops water from getting to the rim joist, thereby keeping the joist dry. Overhanging the decking changes the direction of water flow by redirecting water off and away from the deck joist. It also creates a path for water by leading it away from the rim joist. Overhanging also helps prevent water from getting trapped under the deck joist, thereby making it last longer.

It Enhances Stairs Nosing

Furthermore, Composite board overhanging can improve the overall look of stair nosing. If you attach nosing to your composite stairs, overhanging the decking will make the nosing better. It does this by creating consistency with the stair nosing.

Creates a Pathway for Water

Lastly, overhanging the wood plastic board creates a way for water to flow. However, the gaps allow easy passage of water on the decking. Projecting the board allows water to flow from the deck to the ground without getting trapped under the decking. It helps in preventing the joist and the fascia board from getting damaged by water.

Should You Overhang Composite Decking?

Yes. You should consider overhanging your decking as part of the building plan. Overhanging has a lot of advantages compared to flushing. Aside from the fact that it makes the deck look more attractive, overhanging also keeps water from getting to the joist. It makes the rim joist last longer as well as the fascia board.


How far composite decking overhang is worth considering in decking installation. Composite board manufacturers considered  1 ½  as the ideal measurement for overhanging the deck. It is also advisable to overhang the composite board by one ¾  to 2 ¾ before installing a fascia board.

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