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Footing and Foundation Forms


RobC
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This is how I form my strip footings

The piece of wood suspended in the middle top of the form is the keyway that we are talking about. It is beveled for easy removal.

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This is what it looks like when stripped.

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I feel your pain, this project is getting off to a poor start and you need to get proactive NOW before it escalates into a complete dogs' breakfast.

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This is how I form my strip footings

The piece of wood suspended in the middle top of the form is the keyway that we are talking about. It is beveled for easy removal.

Download Attachment: icon_photo.gif FdnStripFormsKeyway (Medium).jpg

116.65 KB

This is what it looks like when stripped.

Download Attachment: icon_photo.gif FdnStripKeyway (Medium).JPG

134.13 KB

I feel your pain, this project is getting off to a poor start and you need to get proactive NOW before it escalates into a complete dogs' breakfast.

Never seen that done that way before. You must have to take an awful lot of time setting those forms so the top is exactly at the grade line. I've always set the forms, snapped a grade line, and dropped the key after the pour. It sure is pretty though.

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Wow, nice form job. I can't believe you took the time to get the top of the form to exact elevation. Normally we use finish nails to mark the elevation where we snapped a chalk line inside the oversized forms.

Really? I can't recall having ever seen that done in New England or in Oregon. If I'm recalling right, every time I've ever formed up footings, we set them to elevation and used the top of the forms as a screed.

This is what I'm accustomed to seeing. Heck, I thought this was a pretty universal method.

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- Jim Katen, Oregon

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"This is what I'm accustomed to seeing. Heck, I thought this was a pretty universal method."

I have to agree. The trench footings that started this thread are usually reserved for detached garages and small additions, and those are set only loosely to grade, what ever is going on top gets adjusted to meet elevation requirements.

Tom

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Wow, nice form job. I can't believe you took the time to get the top of the form to exact elevation. Normally we use finish nails to mark the elevation where we snapped a chalk line inside the oversized forms.

No rebar in your seismic zone?

Thank you,

The strip footings are THE most critical portion of the building process. I like to get started on the right foot otherwise the project is a series of patches, compromises and bad problem solving decisions.

If you look closely you'll notice two bars hanging from the cross braces and two more resting on grade that will be lifted once the concrete is poured. Generally, builders don't place rebar in footings and only a few in the walls, usually at the top. After all, we want to keep the foundation remediation companies in business. Another story for another time.

I treat all foundations with the same respect, care and attention whether it's an addition, garage or shed. You don't want to make a mistake here that will affect the entire project.

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This shed will stand 5" above grade to avoid moisture entry at the sill plate. It includes a gas line, water, electricity and a 4 pair direct burial communication line. Notice the slab thickening at the edges.

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I guess I'm all mixed up. I thought it was "easier" to do it Rob's way.

Reason being, it's more involved on the front end, but it's less involved on the "back end", meaning the rest of the job, because everything starts out on the correct foot(er).

Either way, I'm liking seeing the Canadian way.

I want to see the insulated forms in process.

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Reason being, it's more involved on the front end, but it's less involved on the "back end", meaning the rest of the job, because everything starts out on the correct foot(er).

It's all the same end result Kurt. Level is level.

Except for all the back filling at the low spots, staking forms in the air, and hoping they don't move or blowout the backfill that you spend extra time on. It's a footer not a swiss watch.

I've have a little more experience with concrete forms than I care to remember between high rise office buildings in Houston to schools and bridges around here, and I've never seen that kind of extra time taken to achieve the same end result. Rob, I'm sure you are nothing less than a quality builder. I was simply stating that I wasn't used to seeing that method. Kurt, seems I must have pissed you off at one time. Sorry about that. Whenever it was.

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Ummmm,.....there's seems to be a prickly bit going on here, and I'm not sure why......

I'll stack up my experience at placing more than a few thousands of yards of concrete against yours, and you know what?

No one with a brain will care.

It's my experience that if one takes each step of the process as far as they can take it, then one has the best shot at getting it right. Rob seems to take steps as far as they can be taken.

I like that. I like that a lot. When I see stuff I like, I want to see more. Hopefully, Rob will put some more stuff up.

Personally, I've always done it similarly, but not with the apparent precision of Rob. It's pretty.

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Not quite as elegant as Rob's method........

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This is the rubber I was talking about. It breaks the capillary path between the footing and the foundation.

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Close up of the rubber; it's a nice step to provide that additional assurance water won't find it's way in. Interior and exterior drain tile is a nice way to go too.

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This is the rubber I was talking about. It breaks the capillary path between the footing and the foundation.

Click to Enlarge
tn_2009819193324_keywayrubber.jpg

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Close up of the rubber; it's a nice step to provide that additional assurance water won't find it's way in. Interior and exterior drain tile is a nice way to go too.

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I've seen this rubber gasket specified at control joints for commercial jobs such as dams, vats or large retaining walls but never on residential.

I'm thinking we may get back to this detail as we progress.

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You know, he just kind of hangs on and pulls it down the line. Then they stuff the rubber in there with a wide knife, and touch it up with a masons trowel. Sounds clumsy, but these guys place a nice foundation.

This particular house has a very substantial amount of finished space below grade, it's deep) and it's finished very, very nicely. The customer was adamant about no water. Zero. Understood.

That means the gasket, interior and exterior drain tile, and that green slime damproofing on the exterior, all the way out over the footing. Lots of redundancy in this one, but it's one of those things you don't want to wish you'd done when you had the chance.

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Reason I'm asking cause it looks like someone erased (Photoshop) the handle off the 2x. If you look at his hands you could fit a handle there to make the work easier. But then I would have used a garden hoe.

Anyway, that's another method of doing it and perfectly acceptable as long as you have the man power. I placed those footings with one helper and that requires all formwork ready to go when the pumper and concrete truck arrive on site. I wouldn't have had the time to go back and rake in a key at least not in the temperatures I was working in.

Does your vertical keyway gasket apply to this kind of construction detail?

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I suppose it would apply to any keyway detail, I'd guess...(?). Honestly, I thought it was overkill, but I like overkill. Like I said, the bsmt. was deep (about 10'), and the guy was adamant about absolutely bone dry. I figured the gasket was worth it (it was another $450 for the entire foundation).

If you're doing your footings with only one helper, I'm really impressed now. That's an ass kicker.

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Wow, nice form job. I can't believe you took the time to get the top of the form to exact elevation. Normally we use finish nails to mark the elevation where we snapped a chalk line inside the oversized forms.

Really? I can't recall having ever seen that done in New England or in Oregon. If I'm recalling right, every time I've ever formed up footings, we set them to elevation and used the top of the forms as a screed.

This is what I'm accustomed to seeing. Heck, I thought this was a pretty universal method.

- Jim Katen, Oregon

Same here.

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Around here they inspect the forms before they let you pour the footings. You can't just dump some concrete in a hole and call it a footing. If it rains and there is mud in the forms you have to pump them out.

I even know of one town that requires a keyway inspection after the footings are poured and before the foundation walls can be started. We often use Rebar instead of a keyway to save time in waiting for the inspection because the rebar is there when the forms are inspected.

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I suppose it would apply to any keyway detail, I'd guess...(?). Honestly, I thought it was overkill, but I like overkill. Like I said, the bsmt. was deep (about 10'), and the guy was adamant about absolutely bone dry. I figured the gasket was worth it (it was another $450 for the entire foundation).

If you're doing your footings with only one helper, I'm really impressed now. That's an ass kicker.

I'm sure it will stop horizontal moisture penetration at the cold joint between the strip footing and wall. But I think we have a bigger concern than a bit of water penetrating at that location. Don’t get me wrong, I’m not saying the gasket is ‘wrong’ I’m saying that we have lost the common reasoning to make this thing work, the macro perspective.

The macro view point is really simple in my mind, build a box underground and keep it dry. You can call it what you like, a daylight basement, walk out basement, crawl space, cellar or whatever; it’s still a box in the ground. Outside of the structural requirements, we want it dry. which btw seem to confuse a lot of builders,

The box is subjected to hydraulic forces from all five sides, water running downhill, uphill and through vapor diffusion.

So, how do we keep the box dry?

Ideally, I’d like to put a really big diaper around the thing and call it a day. But the process won’t allow me.

I start by ‘waterproofing’ the sides of the box with a peel and stick membrane that runs 4â€

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Around here they inspect the forms before they let you poor the footings. You can't just dump some concrete in a hole and call it a footing. If it rains and there is mud in the forms you have to pump them out.

I even of one town that requires a keyway inspection after the footings are poured and before the foundation walls can be started. We often use Rebar instead of a keyway to saves time in waiting for the inspection because the rebar is there when the forms are inspected.

Some jurisdictions get it and some don't.

Who's you daddy?[:P]

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