Poured concrete vs block construction partial below grade

[turtl631]

Looking to build a larger garage. I'm on a city corner lot with an alley and the back yard abutting 2 walls of the garage is 4-5' above grade. Current small garage uses block construction there with stick framing. I want to insulate and heat the new garage with OSB or plywood walls for workshop use. Walls will be 10', and the door side and one other will be pure stick framed. The other two will be half concrete or block. I suppose this is similar to walkout basement construction. Location is Wisconsin so cold is more an issue than heat.

Thoughts on best way to accomplish this? Poured concrete with foam and moisture barrier outside? How best to handle the inside in terms of maximizing space?

 

[billconner]

If you're going to heat it, I suggest ICF from footer to top of stem wall. Insulation and wall all in one, and not too thick.

Otherwise I'm a fan of surface bonded block for easy diy. If contracting it, will depend on contractor. I they own to forms and gear might be less expensive for them to form and add foam.

 

[Firebrick43]

Looking to build a larger garage. I'm on a city corner lot with an alley and the back yard abutting 2 walls of the garage is 4-5' above grade. Current small garage uses block construction there with stick framing. I want to insulate and heat the new garage with OSB or plywood walls for workshop use. Walls will be 10', and the door side and one other will be pure stick framed. The other two will be half concrete or block. I suppose this is similar to walkout basement construction. Location is Wisconsin so cold is more an issue than heat.

Thoughts on best way to accomplish this? Poured concrete with foam and moisture barrier outside? How best to handle the inside in terms of maximizing space?

As Bill suggested, ICF is going to be the best from the energy efficiency cost and from a strength cost. If its a simple rectangular structure stacking the blocks and installed the steel reinforcement is a DIY if you so choose. You will need help during the pour.

Surface bonded dry stack block is another possibility for DIY but I would also fill cells with a vertical rebar and peacrete every 2' if there is a significant amount of the height of the wall buried.

Your description is not real clear. How much of the concrete(in whatever form) wall will be below grade?

 

[turtl631]

Not looking to DIY any of this. Just want to have some idea of what makes sense to be discussing with contractor.

It will be around 26x28, and two of the walls are 4-5' below grade majority of their length. The yard originally was all that height with retaining wall and then a flipper built a garage in by excavating a section and building a 20x22 garage with block walls.

 

[turtl631]

New garage will be extended towards alley and neighbor's property as indicated by yellow line. House and yard grade is 4-5' above sidewalk/alley grade. There is block wall along alley as well as the deck.

I'll check into ICFs as well.

 

[Firebrick43]

If you go poured walls instead of ICF there is another product that is sort of like half of an ICF called InSoFast. It has plastic studs embedded in the foam to provide a place to screw panels to. I don't know of the drainage situation at your sight but there are grooves on the back that any water/moisture that does make it thru the concrete wall then runs down the channels to a perimeter drain on the floor. This is better IMHO than wood studs/fiberglass that will mold with moisture. Of course a dimpled drainage membrane should still be used on the outside of the wall.

 

[ConCretin]

ICF is fine but it's probably not the most affordable option especially if you are going to hire it out. it's hard enough to find contractors these days and there aren't a lot with the interest or experience with ICF. Plus you have to cover the foam with something, which adds a layer of expense.

When I built the Concrete Underground, I used traditional CIP concrete for the foundations and ICF above grade where the R value was more beneficial. I still believe this was the way to go.

Either block or CIP with a layer of rigid insulation will perform just fine. I'd base my decision on price and availability and get going on my new garage. Good luck!

 

[theoldwizard1]

No matter what you choose, proper exterior waterproofing, below grade and DRAINAGE is extremely important !

I would also go ICF but probably 3 walls. Same exterior waterproofing requirements.

Stacking the blocks is easy. The trick is leave a seam, top to bottom, in each wall. This is where you adjust for any minor differences in the blocks.

 

[kwb]

Looking at that satellite view - check on setbacks before you spend any more time on how you do this. You might be at a dead-end before you even start.

 

[tarmy]

Looking at that satellite view - check on setbacks before you spend any more time on how you do this. You might be at a dead-end before you even start.

This. Check with your planning dept about what you can build…then go to building dept and see what they will allow. Many jurisdictions will not allow certain construction types that haven’t been approved/incorporated into their code. Also, there are fire rating issues in certain jurisdictions where the structures are within 3’ of a PL.

 

[paredown]

It's probably worth mentioning that if the block sections are acting as retaining walls (which 4'-5' below grade sounds like they are), you will likely have to parge the blocks and add rebar. Not sure if surface bonded would be OK -- that's a question for your local building codes.

Depending on finding the right concrete guy, the nice thing about poured in place is that it is fast and efficient--the pro crews have hundreds of thousands of dollars invested in quick strip forms and can set up fast and efficiently and once the footing is done, the setup and pour are pretty quick.

Setbacks--they can be a killer!

 

[turtl631]

should be okay with setbacks. can't go any closer towards the street though, there is a parking pad with a vehicle parked on it in the satellite picture. initially had hoped to build a three-car wide garage but that is pipe dream with the setback issue. I will do some investigation before planning out anything further.

 

[CraigStu]

I know this is different but when we had our house built 4 years ago I asked the builder about forundation. Block or poured. He asks if I want block. I said no. He says good because I would tell you I will not build w/ a block foundation. He said that longterm block just has too many problems and he will not get himself into having to fix them. I believe ICF is also a very good option but I would not even consider block.

 

[andyvh1959]

I'm with the ICF, if you can find a good contractor to do it. Like said earlier, proper backfilling, drainage planning and grade planning is almost more important than the construction itself. You can take advantage of the grade difference on the side and back away from the alley with plastic drain tile set outside the ICF wall. Once the wall is in I'd backfill it with gravel about 12" out from the ICF up to within a foot of the yard grade. Then use soil fill to yard grade or some type of decorative stone to maintain drainiage. So the yellow line is on the alley side, at alley grade? Or is the garage slab at least 6" to a foot above the alley surface grade? Milwaukee can get some good snow amounts and rains and you don't want the alley side being the water side since you can't control whats happening in the alley.

 

[dcg9381]

Our "basement" is poured concrete, tar based moisture barrier outside, french drain behind, foam inside (within framing).

I had a situation just like the OP a a prior house. 8' off grade though, we put in a retaining wall. For us, it was substantially less expensive to put in the retaining wall and build a traditionally framed garage. Course, you don't get the same amount of space with a retaining wall.

I know the OP said the setback is fine, but I would assume you can't build all the way up to that grade (unless the property line is further south).

 

[billconner]

I know this is different but when we had our house built 4 years ago I asked the builder about forundation. Block or poured. He asks if I want block. I said no. He says good because I would tell you I will not build w/ a block foundation. He said that longterm block just has too many problems and he will not get himself into having to fix them. I believe ICF is also a very good option but I would not even consider block.

Basement wall or plain frost wall with fill both sides? I kind of agree if basement (though just talked to someone who built a block basement - surface bonded - and no problems in over 20 years).

I built my garage on rubble trench foundation with surface bonded block walls above grade (50"inside, 12" outside) and no problems - and there is standing water everywhere. Surface bond cement is waterproofing afterall.

 

[rayra]

City? What's the frost depth in Milwaukee. You'll likely end up with a deep concrete perimeter footing and insulation under the slab. ICF would be nice. Depends on your local regs.

 

[andyvh1959]

Frost depth im Milwaukee is about three feet. A detached garage like the OP decribes would be on a floating slab, but the weight of a concrete wall five feet high would likely require a footing below the frost line. with one side of the slab pinned to the foundation side. Insulation under the slab is only required if the OP wants to heat the space and minimize some heat loss.

 

[CraigStu]

Basement wall or plain frost wall with fill both sides? I kind of agree if basement (though just talked to someone who built a block basement - surface bonded - and no problems in over 20 years).

I built my garage on rubble trench foundation with surface bonded block walls above grade (50"inside, 12" outside) and no problems - and there is standing water everywhere. Surface bond cement is waterproofing afterall.

Full basement. Attached garage on one end w/ walk out door from basement on the other end. I thought somewhat similar to OPs garage since our ground slopes from first floor level to basement level over 39ft width of the house.

 

[billconner]

Full basement. Attached garage on one end w/ walk out door from basement on the other end. I thought somewhat similar to OPs garage since our ground slopes from first floor level to basement level over 39ft width of the house.

I agree that plain block laid traditionally with mortar is probably not the best choice for basements or similar unbalanced fill construction. Since I find it much easier to diy than forming and pouring concrete, I might use it but surface bonded and with water management dependent on the conditions.

 

[CraigStu]

I first read about the surface boned block maybe 8 yrs ago. I haven't had a project to use it on yet but I keep it filed because I agree. Seems perfect for a diy'er.

 

[backupbeeper]

We looked at icf but couldn’t find anyone who even knew what we were talking about so we did poured in place

A lot of your decision will be limited by what your city inspector allows

But I would verify the setbacks and get the lot surveyed before you do anything .

 

[WNYflyer]

Sounds like there will be appreciable differences in interior and exterior grades at some garage foundation wall locations. That said, besides the lateral soil pressure on the foundation wall due to the unbalanced fills ( i.e. retaining wall ?) make sure any additional lateral soil pressure due to a vehicle driving next to the wall is addressed if that would be the case, aka "surcharge" load.

 

[BombShelter]

ICF was hot 10-15 years ago but I never see anyone using it these days. We see issues where it traps water next to the foundation and then when that first crack starts, usually in a corner, all of that trapped water drains through the crack.

We have extreme weather conditions up here, -10 in the winter up to 90 F in the summer, add in a ton of water and the foundations take a beating. I've looked a thousands of basements and foundations, block or poured? It's a toss up, they both have issues. I just looked at two poured foundations today (neighbors), maybe 25 years old and they both had several floor to ceiling cracks and it looked like rusted tie-rods. Drain-tile will not capture water that comes in above the floor like these were doing.

I would insulate on the inside and not the exterior and waterproof the below-grade exterior with CETCO Swelltite. They don't usually put drain tile in garages up here because they'd freeze up in the winter. I've seen new garages (with below-grade walls) leak after the first snow melt and the contractor is crapping his pants because he didn't offer the customer a waterproofing option. If you want to go for gold, put CETCO Voltex DS under the floor before they pour, it will stop water moving up through the floor.

 

[billconner]

I never see anyone using it these days.

My neighbor built a 3 car garage last year, embedded into a slope with ICFs. Seems fine. They generally are pretty popular in this area.