New deck Issue - "Between a Brick and a Soft Spot" (kinda long)

[RonB]

We live in a newly constructed home with brick exterior and a basement. The basement was dug and completed in August of 2008, so it has been finished and back filled for about 18 months. I have been letting things settle before I added a deck. We are planning to build a deck which will be irregular shaped but not all that large. Description of the size and shape:

- There is a cove in the side of the house, and under the roof line, that is approx. 13'6" wide and 6' deep (from the face face of the house)

- The deck will extend an additional 8' from the edge of the house, and about 20' from one end of the cove.

in other words the deck is "L" shaped with a (20'x8') leg and a (6x14') leg)'. About 245 SF.

I realized from the start that attaching a ledger to brick was a no-no for most codes and I had no problem with a free-standing deck....until now. I had not considered the soil compaction issue with our new basement construction. I know the basement guy left some virgin soil inside of the cove but the 2' to 3' outside of the basement wall is disturbed. ditto the wall along the longer length of the L. We have back-filled from settling several times since construction and the area under the roof seems to have stabilized. I was able to get under there with the rear end of a bobcat last fall and didn't leave much track.

The Problem: Footings for the free-standing deck in area closest to the basement foundation. I don't relish the idea of digging 8' footings, especially under the roof overhang - almost a had dig. I had considered going down to frost line (about 3' here) and pouring slabs and then tube footings on top.

Any help would be appreciated.

BTW, the backfill, and surrounding soil is good old SE Kansas clay. That probably doesn't help either.

Thanks RonB

[Colbyt]

Really?

That is the only approved way of doing it here. Big bolts and some fine print but that is the method.

Are you sure of the code in your area?

[hrhofmann]

Are you way out in the country or in/near a town that has zoning/ construction restrictions. That is your first consideration. If you can build close to the foundation, especially in the areas that are shjielded form rain by the overhang, I woudl flood that area with water until it is REALLY saturated and then try to tamp it down repeatedly. You may need to flare out the footings for the deck supports so that they rest on a larger bas than just a straight down hole. Soil continues to settle for several years and if I could, I would wait at least another freeze/thaw winter before building, even with flooding the area.

[RonB]

Actually we live in a rural area that is code-less. But I want to do it in right. Our old city and dozens of codes I have researched prohibit attaching a deck to brick or stone veneer. Main concern with brick is the ability of the bricks to handle the levered load from the sill plate attachment. But overall the biggest concern is water intrusion behind the brick and rotting the sill plate.

In researching I repeatedly came across "Design Code for Acceptance, Prescriptive Residential Wood Deck Construction Guide" (American Wood Council) . It expressly prohibits attachment to or through exterior veneers (Brick, Masonry, Stone).

I'm a crotchety old fart but when someone throws stuff in front of me enough, I eventually believe it :^}

RonB

[Colbyt]

Actually we live in a rural area that is code-less. But I want to do it in right. Our old city and dozens of codes I have researched prohibit attaching a deck to brick or stone veneer. Main concern with brick is the ability of the bricks to handle the levered load from the sill plate attachment. But overall the biggest concern is water intrusion behind the brick and rotting the sill plate.

In researching I repeatedly came across "Design Code for Acceptance, Prescriptive Residential Wood Deck Construction Guide" (American Wood Council) . It expressly prohibits attachment to or through exterior veneers (Brick, Masonry, Stone).

I'm a crotchety old fart but when someone throws stuff in front of me enough, I eventually believe it :^}

RonB

Well that makes two of us old farts.

May I point out a few common sense things for you to think about.

There is no leveraged load on a properly built deck. The ledger side supports half of the load. The piers on the other end support the other half.

Properly installed flashing will prevent water infiltration behind the ledger board. This step is often omitted by budget builders.

I freely admit that I have not built a deck or looked at the code since

2000. Things may be different now. All the ones I built prior to that are going strong, staying level, no water infiltration and the walls have not fallen down. They are a PITA to maintain and patios are all I will ever build in the future. .

Colbyt

[benick]

That is SO TRUE about decks...They are a PITA and generaly look like crap after a few years no matter what you build them with ....Mine will be flat rocks set in sand or pavers...LOL...

[hrhofmann]

I built my deck using TREK for everything but the main joists which were pressure-treated. But, I attached the ledger board to a wooden exterior house right at the sill level so I didn't have your situation. Could you bolt the ledger board thru the brick facade all the way thru whatever is behind the brick, into the sill plate or the joists right above the sill plate? It might take 8 or 10 inch long bolts, and if there was any future lateral pulling, you would need to make sure the sill plate was anchored to the top of the foundation, not just resting on the top. It should be secured, but I don't know how careful your builder was and how closely you watched him during the building proces.. .

[RonB]

. =A0Could you bolt the ledger board thru the brick facade all

What I was originally concerned about even before we built the house was tightening down the ledger and maybe fracturing the masonry since there is an air gap behind it; and frankly bricks are mostly hollow these days. I thought maybe I could overbore holes and install a spacer/washer arrangement to put the stress on spacer, not the bricks.

When I started looking into that is when I found out that most codes and architectural standards that address decks on brick just forbid attaching it. The code concerns don't address compression of the brick wall. They address:

- Stress on the brick itself. The brick and airspace behind it are

3"- 4" thick. With a lag screw screwed into the sill, you are dealing with a torsional load. The lag screw is fixed at the face of the sill and the weight of the deck is 3-4" away with the bolt weighing on brick....a rather brittle substance.

- Moisture. The real big deal that constantly came up was water intrusion. Apparently brick, as a rough, porous material, is hard enough to seal without boring holes every 16" or so. The concern is that, even with flashing, moisture is going to get in behind the flashing, through the holes and attack the sill.

I spoke with our son this evening. He is a construction superintendent for a commercial contractor. He is bringing a compactor up in the weekend or two. He thinks some serious pounding out a foot or so from the foundation wall will tighten things up quite a bit.

Ron

[aemeijers]

Colbyt wrote: (snip)

Don't forget frost heave making the deck act like a lever. Not a problem with proper piers, but low decks are often merely on blocks ar grade, or resting on buried patios. I can tell my buried patio is frost heaved- the ponding against foundation made a good mosquito breeder, and lots of it seeped through poor foundation sealing into the basement, until I scraped drainage swales through the planint beds around the deck, and cleaned the debris from under it.

Like my idiot previous owner... :^( No flashing (not even under the sliding doors), no standoffs, ledger board screwed right to the damn siding. Evidence of previous water leakage, and some damage, down in the basement in the spots where the flashing should have been.

Yeah, I have considered tearing out the deck, and resurrecting the buried concrete patio below. But my place is raised up, and having two steps down from the sliders to the patio would be a pain, and it would make the rooms facing the sliders seem smaller. And the addtional two feet above grade makes the deck feel a lot cooler and less muggy than walking out in the yard in summer.

So, I need to replace (or at least reskin) the deck, and add flashing and space between it and the wall. And the rotted siding and sheathing needs replacing at the same time. At my age, I have more cash than ambition, so I'll probably hire it out. But I have been less than impressed by the self-employed tradesmen around here, and choked on estimates provided by 'real' contractors. (who I suspect aren't really interested in my tiny jobs.) So do I let it slide, and just lower the asking price in 2-3 years, or pay enough to make me cry and not get it back at resale? Decisions, decisions. Times like this I miss having a SWMBO in the house.

-- aem sends...

[Tony]

Will the deck ledger be above or even with the basement walls? If above the foundation wall, how high above is it?

If it's down as low as the basement walls, just drill all the way through to bolt it on. It's not depending on the brick. If it's up above, you can get creative if it's not too far above.

[RonB]

That would be getting a little low. Besides, I would have to remove basement sheetrock to get access.

As it is, if I had bolted into the sill plate the deck would have been about 2' off of the grade and could have been close to the house floor level. Gettin' older and we are trying to maintain same-level access in case one of us gets gimped up. Going down to the basement wall would put the deck on the ground with 1-2 steps to get to it. Besides, boring holes on 16" centers in concrete gets cumbersome.

Ron

[hrhofmann]

If you have access to the foundation, connect ot it and then add additional height to the board bolted to the foundation

[jamesgangnc]

Doesn't this mean you will have steps between the deck and any entrances to the house? Seems to me that it would be preferable to have a level transition there and leave room somewhere for a ramp between the ground and the deck on the perimeter in case you need handicap access.

[Joe]

Have you considered that all that pounding could easily put the foundation wall into the basement? Happened locally to an unwary lad, but fortunately it was a block wall that could be repaired fairly well. If it happens with poured concrete, the fix cold be spendy, indeed.

Joe

[RonB]

No - the plan is keep the deck as close as possible to the house floor.

[RonB]

Yeah. We are going to chat about that a bit before we do it. I think he is planning to do the tamping a little farther out from the actual foundation wall. I told him I was more than willing to cantilever from piers back to the deck, 1'-2' if necessary. He knows his stuff pretty well. Has a degree in construction management which is about

1/2 engineering, and 12 years on the job.

RonB

[krw]

I did something similar when I replaced a deck on my Vermont house, about fifteen years ago. The outside of the deck was sitting on the ground and would shift up in the winter, forcing water against the rim joist, which rotted, along with the sill. I decided to make the replacement free-standing so no water would be trapped. I put tubes down 4' all around, which obviously wasn't enough. The outside ones pushed out of the ground 4"-6" per year (the ones toward the house were fine). Every year I had to relevel the deck and every other I had to rent a concrete saw to cut the pillars until they were completely out of the ground. I then put the deck on blocks and all was well. It would still shift up, but would go back down in the spring.

Making a free-standing deck solved one problem but I should have just let the deck float on top of the waves. ;-)

[aemeijers]

Funny how Mother Earth spits some things out, and swallows others. My grandmother's house, built in 61, had a back porch that was orginally an inch or two above grade. By the mid 70's, the turf was growing over it. It was a well-laid porch with good footers, and never moved or heaved. The back yard got taller. We had to put extensions on the widow wells around the basement windows, too. It got to be routine- about once a year spend a day with a shovel, edging and cutting drainage swales to keep water from ponding against the house and filling the window wells.

-- aem sends...

[Evan]

:

4 feet is the "typical" depth for going down below the frost line...

It sounds like you need to go down beyond that due to unique soil/drainage conditions on your site to not have your pier footings for your deck heave up and out of the ground...

Some unrelated advice, based on what you are describing with your deck, you have A LOT of moisture in close to your foundation... Be very vigilant about repairing any cracks or leaks you may find as with a lot of moisture right outside the foundation combined with poorly draining soil that acts like a sponge, a small crack or leak could quickly become a big one when winter comes...

~~ Evan

[krw]

That doesn't even come close to the actual frost line in VT.

Yes, but deeper wasn't an option because of rock. I think the real problem is that I should have backfilled the piers with gravel instead of dirt. I

*think* what was happening was that the soil (clay, really) was saturated with water in the winter and grabbed the pillars as it expanded. In the spring the stuff turned to mud (spring is called "mud season" in VT) and filled in under the pillars so they couldn't go back down. It was easier to just let the deck float on the ground, though. HomeDespot had blocks intended for this.

I sold the house two years ago and move out of the Peoples' Republic of Vermont. ;-)

Yep, clay soil absorbs water like a sponge and expands. Freeze it expands even more. The house itself seemed to be alright and the posts around the foundation didn't move much. There was an unheated "crawlspace" (it was 7' deep, but no access to the basement) on the other side of the foundation there so it did get cold, though perhaps not as deep. There were no signs of water in the basement or any cracks in the 8" poured wall. The basement wasn't very deep, evidently because they hit ledge when they dug the hole.