How much screening underneath deck blocks?

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Posted by: from Milton
8/5/2015 at 10:40:19 AM


I am building a floating deck in my backyard this weekend. The backyard has a minor slope of 5". This will be a ground level deck with 22 deck blocks based on the deck design (375 sq/ft).

I live in Milton,ON which is 2" of dirt then solid clay and was wonder how many inches of screening I should have under each deck block as a solid base?



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Date/Time8/5/2015 at 12:40:05 PM

Use 4 to 6 inches. Sorry that's auto correct.

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Date/Time8/5/2015 at 2:13:49 PM


A bare minimum of 2" but 4" to 6" is better. The first step is to remove the dirt and get down the the clay as it is a much more solid base. The gravel/sandy base helps drain water away from the deck posts and lessens the chances of movement. Enjoy your deck.

Regards from the west.


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Date/Time8/5/2015 at 11:59:49 PM

Because the clay is so close to the surface I would check to see what others have done in your area successfully. I'm concerned that if you only remove clay where the deck blocks will be sitting, you will be basically creating clay pots for water to sit in. Even with screening in the holes.

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