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Building floating deck using deckblocks (free-standing piers)

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  • Sep 15th, 2009 11:34 am
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[OP]
Newbie
Mar 6, 2007
27 posts

Building floating deck using deckblocks (free-standing piers)

Hi there,

I'm planning to build a floating deck (18 inches off the ground) and am considering using deck blocks as opposed to set concrete supports. I'll be digging out all the topsoil where these deck blocks will sit.

I was wondering how many inches of screening do I need to put under each deckblock. Also, do I need to lay any type of gravel (ie. 1/2 inch or 3/4 inch gravel) under the screening; and if so, how many inches. Any information or input you could provide would be greatly appreciated. Please note that this is for a house that is one year old (this is our second summer in the house). Not sure I need to take this into consideration, but just thought I would mention it.

Hope to hear from all the DIY RFD'ers who have built decks using this product in the past.
21 replies
Deal Addict
User avatar
Jan 13, 2004
3682 posts
267 upvotes
I've never made one myself this way, but have helped two different friends and also my nextdoor neighbour do one.

Why would you remove the topsoil? The whole point of deck blocks is to just drop them right on top. Since you're going to need posts either way, you have nothing to gain by removing anything.
Everything in moderation... including moderation :twisted:
Deal Expert
User avatar
May 10, 2005
25442 posts
2675 upvotes
Ottawa
Mine is a floating deck and has been there for many years. I made a 30X30 inch square, dug 8 inches down, laid landscape fabric and extended the fabric out a couple feet in each direction, put in stone dust for a few inches and filled to the top with gravel. Then put 24 X 24 patio stones on top. The deck blocks went on that. I have no problems.
The landscape fabric keeps the stone from being swallowed up by the clay subsoil.
Deal Addict
Feb 7, 2006
1872 posts
501 upvotes
Made a couple of decks with these. Very easy. Deck block website states they can go onto soil but I put in a fabric and gravel base.

Deck blocks
Sr. Member
User avatar
Jul 13, 2006
887 posts
20 upvotes
I spoke with one of the main designers/engineers at DekBlock and he said that as long as the soil/land is settled (one or two winters since they back-filled), then just put the dek-block right on top of the soil, no digging/removing of anything is necessary.

Mine was built this way, and has stayed perfectly level for over 2 years now, including a winter where the deck had over 5' of snow on it.
Newbie
Aug 28, 2006
46 posts
deckplans.com gives you all the info you need. I sectioned out the footprint of the deck and put down good landscaping fabric and 3/4" gravel (2" thick) because I don't like weeds under my low deck. I tamped down the points where the blocks go, just to make them more level and stable. Put the blocks right on the gravel. Built a 24x30' deck single-handedly. It took 80 blocks but they went down easy.

Only 1 year old but no sign of structural issues. Keep a close eye on it in the first winter (frost heave), no problems as long as you have 1/2" gap to the house.
[OP]
Newbie
Mar 6, 2007
27 posts
Thanks everyone. Appreciate your feedback.

However, I do have one question. When you said that you used gravel, are you referring to 3/4 gravel? 1/2 inch gravel? Or screening?
Sr. Member
May 24, 2003
931 posts
42 upvotes
Sounds like the Mike Holmes way of overkill using Dekblocks. Just put them on top of the ground and you will be fine. They are designed to be used like this.
Deal Addict
User avatar
Jul 26, 2004
3356 posts
60 upvotes
Ontario
I have 2.5' x 2' patio blocks in my backyard. Can I put these deck blocks on top of those where my deck will be? I want to minimize back breaking labour to get rid of some of them. The house is about 35 years old and most likely settled.
Member
May 17, 2007
369 posts
4 upvotes
I am about to start building a deck, I am interested in this design as this is without digging holes, and concrete. How much these deck block costs? Is it city (waterloo/kitchener) standards? Where can I buy those? I am building 16'x16' deck, one side attached to my home and other side with three posts.
Deal Addict
User avatar
Feb 14, 2009
2241 posts
135 upvotes
Green_Star wrote:
Jun 16th, 2009 1:29 pm
I am about to start building a deck, I am interested in this design as this is without digging holes, and concrete. How much these deck block costs? Is it city (waterloo/kitchener) standards? Where can I buy those? I am building 16'x16' deck, one side attached to my home and other side with three posts.
Out west if the deck is attached to the house you can NOT use deck blocks. These are for 'floating' decks only. If it's attached to the house you will need a permit as well vice no permit (usually) is required for a floating deck.

And for a 16' x 16' deck you will need more than 3 supports ;)
Member
May 17, 2007
369 posts
4 upvotes
mcplar wrote:
Jun 16th, 2009 1:59 pm
Out west if the deck is attached to the house you can NOT use deck blocks. These are for 'floating' decks only. If it's attached to the house you will need a permit as well vice no permit (usually) is required for a floating deck.

And for a 16' x 16' deck you will need more than 3 supports ;)
Yes, for 16' x 16' deck, I thought I need more supports, but home depot guy designed it, before him there are many other guys tried with 4 and 6 posts. And the home depot guy told me as long as my deck height is under 2', I do not need permit even though it is attached to house.

I know I should not attach it to house if I want to go with deck blocks.
Newbie
Aug 28, 2006
46 posts
General Advice: You can be as close as 1/2" from the house and still be detached. If you use dek blocks you should NOT attach the deck to the house. The deck WILL move relative to the house, that is why it is called floating foundation. Just keep 1/2" gap to the house and you are golden.

Ledger boards attached to the house only help minimize the old school footings you need for an attached deck.

Also, the number of blocks does not equal the number of footings. blocks use 2x6 beams but the footings use 2x8 or 2x10. So the max spacing for blocks is 66" and you WILL need more than 3 blocks for a 16' x 16' deck. More like 32 IF you use 2x6 decking boards (24" joist span). Go to http://www.deckplans.com/free-deck-plans and design your deck for free, it is that simple.
Jr. Member
User avatar
Nov 15, 2004
143 posts
1 upvote
I built the deck below using Dek Blocks and found their website had all the info I needed. I would high recommend them to anyone. And, no, I am not associated with Dek Blocks in any way...

Image
Deal Addict
User avatar
Jul 26, 2004
3356 posts
60 upvotes
Ontario
dgmorr wrote:
Jun 16th, 2009 10:49 am
I have 2.5' x 2' patio blocks in my backyard. Can I put these deck blocks on top of those where my deck will be? I want to minimize back breaking labour to get rid of some of them. The house is about 35 years old and most likely settled.
Anyone with info on this?
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