4 posts / 0 new
Last post
How much gravel

I am digging 11 12" wide, 36" deep holes with a PHD this weekend for my new 12x16 deck. I will be using a bag concrete as a base at the bottom of the hole, and then will be using 6x6 posts.

How much gravel will I need to fill the rest of the hole around the post?

Thank you in advance, especially if you have any additional tips -- My first deck!


There are a few things you have to review. Around here we do it differently.

1 .How tall is your deck? Posts are usually 4x4.

2. Post holes are filled with concrete to the top of the opening (I add rebars to the concrete), then a Simpson post connector is inserted into the concrete at each hole. When the concrete is hard enough, the posts are bolted to the connectors.

3.Depending on the height of your deck, for a deck your size, you don't need 11 holes.

There are other ways of doing it, but I've been doing it my way for years and never had a problem.

Around here we do it differently, but first, how tall is your deck going to be?

1. I doubt that you need 11 posts, and they don't have to be 6x6. 4x4 posts are common.

2. I fill the holes with concrete and rebars to the top, then place Simpson Post connectors.

3. The posts will be bolted to the SPCs.

Just make sure your holes are below your frost line. I advise pulling a permit and have the holes inspected and approved.

Re: How much gravel

The reason for the 11 posts is because of the shape of the deck... not a square, but actually a 45 degree edge.

I picked 6x6's because the deck will be an extension of an existing deck, so I sort of wanted to match the look.. Plus I figured for a little more money I could guarantee the stability and life of the deck. Believe it or not, I have been to make other forums where they freakout the moment you mention using 4x4's anymore for posts, and to only use them for railings...

I didnt go with concrete pillars because i figured that would be a fairly hefty amount of concrete.

Re: How much gravel

"I didnt go with concrete pillars because i figured that would be a fairly hefty amount of concrete".

True, except you need the concrete to hold the posts securely. Gravel and rock alone won't be enough.

There was some news lately about deck falling down in Florida...do you want this to happen to you?

Sponsored Stories

TV Listings

Find TV listings for This Old House and Ask This Old House in your area.