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Deck - to attach or not to attach to house

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  • Sep 13th, 2011 11:17 am
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Deal Addict
Sep 2, 2003
1155 posts
97 upvotes
mart242 wrote: If you attach it to your house you'd better be sure that the other end of the deck will definitely WON'T move. ie: dig to the frost line and pour lots of concrete.

If this is done by a pro...not that they dont do shabby work...but they should know to dig 4 feet
Deal Addict
Oct 22, 2002
2040 posts
526 upvotes
'sauga
dgmorr wrote: Does the deck attach to the rim board of the house or does it go through the floor joists as well? How do you guys figure out where the joists are without cutting into a finished basement to see?

Typically the joists of the deck are hung off of the ledger board, which is attached to the house. Note that the ledger board cannot be attached to brick veneer, it needs to be attached either to the concrete foundation (with sleeve anchors, time to break out the hammer drill) or to the rim joist inside the house (with carriage bolts and washers) - you will need access to your floor joists to do this.

If you have a newer home made with engineered floor joists or a foundation made of concrete blocks this becomes much more difficult and a free-standing deck may be the best option.
Deal Addict
Sep 2, 2002
2120 posts
47 upvotes
abstract808 wrote: Typically the joists of the deck are hung off of the ledger board, which is attached to the house. Note that the ledger board cannot be attached to brick veneer, it needs to be attached either to the concrete foundation (with sleeve anchors, time to break out the hammer drill) or to the rim joist inside the house (with carriage bolts and washers) - you will need access to your floor joists to do this.

If you have a newer home made with engineered floor joists or a foundation made of concrete blocks this becomes much more difficult and a free-standing deck may be the best option.

Excellent answer. I see decks attached to brick veneer all the time, and this is definitely the wrong way to do it. Brick veneer is a veneer - not structure. Also, deck builders love to simply drill holes in the brick and install expansion anchors. Long after the contractor is gone, water gets in the brick, and never dries out because it's shaded by the deck. In a few years, the brick will start spalling.

Problem is, spanning that distance with carriage bolts is very difficult. If your ledger board can't be against a concrete foundation wall, it's just so much better to simply install a couple more sonotubes and have the deck detached from the house.
Deal Fanatic
User avatar
Aug 22, 2001
7099 posts
329 upvotes
Toronto
guys, im building my deck right now, and i got all the permits for house, and decided to go this route with my deck as it did not require a permit and I found the best decision to last the longest and be the safest.

sono tubes 4x4 PT - 4ft deep, max 8 ft span. 2x10 beams with 2x8 joists. only about 20" of the ground, so its 3 steps. at that height, its considered landscaping, and can be any size, no permit required in Toronto. less than 24" off the ground, so no railing is needed, but im installing one anyways.

max fence height 6'. avg railing height 38-42" max 4" (100mm) between pickets in railings. railings and fences can be any design, as long at they are not easily climbable for safety.

I asked all the questions, had the inspector look at it, and everything was a-ok (he was there to pass some basement work).

if you attach the deck to your house, you will need a permit.
as said before, it has to be properly anchored into structure.

if you got the money, go for 6x6 instead of 4x4, but they are over double the price.
Deal Addict
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May 24, 2008
3488 posts
1532 upvotes
Toronto
No need to attach to the house. You can build a free standing deck that sits right up against the house. It will look just the same and will be just as strong. We just finished our deck and we used full height concrete supports instead of PT posts. This provides better lateral support for a free standing deck. The deck is absolutely dead solid.
Deal Addict
Nov 20, 2003
1287 posts
272 upvotes
Aurora, ON
My low platform deck rests (loosly attached) on a ledger board that is attached to poured foundation. The other end of the deck is on posts that sit on poured concrete (4' deep sonotubes). This deck is not going anywhere. No problems over four years with anything.

However, having said that, should I ever build another deck I'd strongly consider using screw posts instead of sonotubes. There are huge advatanges to be gained if one uses screw posts. They can be installed in one day. No need to wait for concrete to cure. No need to dig anything out, figure out where to dispose extra soil. The posts can be adjusted in height and even repositioned if necessary.

I build the deck pretty much by myself, and the foundation was the biggest pain in the butt. It also cost me probably $1,500 for all the sonotubes, concrete, post hole digging, and extra soil disposal. I have something like 18 sonotubes (500sq/ft two-level platform deck. custom layout). I'd gladly pay someone same money and be done in a single day with no mess to deal with.

There are a number of companies that offer such posts now. They are all called differently, but idea is the pretty much the same: a giant screw that goes 4'-or-so feet into the ground, and will last for decades.

Some links:
http://www.sears.ca/product/mayne-posts ... 68968-580D
http://www.marsdenbros.com.au/krinner
http://www.amazon.com/Achla-Designs-Gro ... B000FJTXW2

Here's Canadian company that definetely has local dealers:
http://www.technometalpost.com/en/home/

I think I also saw ads in a local Rona and Home Depot stores for similar companies.

Bottom line, if such posts can be installed for about $100-$150 each than it's something definitely worth considering.
Deal Addict
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May 24, 2008
3488 posts
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Toronto
I like the idea of those screw posts, but I'm skeptical about their compressive strength and their ability to withstand frost heave. They are narrow at the bottom which is exactly where you want them to be wide and strong to support load. Also, the threads on the screw provide the perfect "handhold" for frozen soil to heave this upwards.

I don't doubt that they work, but if I did my deck again I would still use concrete piers (sonotubes) sitting on concrete footings in a 4' hole. A lot of work, but the deck sure isn't going anywhere.
Deal Addict
Sep 2, 2002
2120 posts
47 upvotes
Little Tim wrote: I like the idea of those screw posts, but I'm skeptical about their compressive strength and their ability to withstand frost heave. They are narrow at the bottom which is exactly where you want them to be wide and strong to support load. Also, the threads on the screw provide the perfect "handhold" for frozen soil to heave this upwards.

I don't doubt that they work, but if I did my deck again I would still use concrete piers (sonotubes) sitting on concrete footings in a 4' hole. A lot of work, but the deck sure isn't going anywhere.

Seconded. A coils system can work, but these are effectively pins in the ground. They rely on shear strength of the soil (not bearing capacity), and frost could use that shear strength to heave the screw post. You want something with smooth sides at the top, and this system doesn't provide that.

In areas where the soil is not susceptible to frost, they might be a solution for a deck, but I have my reservations. Helical coils are not uncommon for remedial work in residential areas for foundations, but those are all completely below frost depth.


Edit: Thinking of these ground screws some more, I'd be tempted to look into them for fences. But there are still the concerns with hitting rocks on the way down, etc. Maybe for intermediate posts, and do all corner posts with sonotubes...? It's an interesting idea.

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