Garage building advice...
#31
Intermediate
Good advice above; I'll add the following.
I suggest that making it bigger might include more than just a foot or two in the exterior dimensions. If you have the space and money add another garage bay in addition to the additional 1-2' per side. Consider space for your tools, garden tools, auto tools, and spare parts bins. I have a lot of these bins myself. I have never, ever, heard anyone complain that they have too much garage area.
On the garage floor consider a thicker than the typical 4" thick slab on grade. Often a 4" slab design results in an installed 3" to 5" thick slab because the grade prep is not perfectly level. I have never used the suggested fiber reinforcing but if you do use it,it should not take the place of steel reinforcing. And the reinforcing should be as much as you can tolerate. If you can see your way to #4's at 12" OC EW do it. This will also help with crack control. The contractors don't like 12" OC spacing because they can't fit their boots between the bars. If you do use 12" spacing have them install a lot of dobies to preclude them from forcing the bars down to the bottom of the slab by stepping on them. Have the contractor saw cut some control joints; spacing should be less than 10'.
If you want a lift, the two post kind, I suggest that you scoop out some subgrade and create a large footing centered under the lift posts. Pad footing size would depend upon your lift size and lift capacity. I would create a minimum 5' square, 12" thick pad footing under each lift column. Use #5 bars at 12" OC EW 3" clear from the bottom. Pad footing can be monolithic with the slab or placed separately. The thickness should be at least 12" even if a slab is place over the top during a subsequent pour. Lift post base plate anchor bolts should be installed such that they extend the mfg requirements for embedment into the footing. The AB embedment depth would be different between the monolithic footing-slab pour and the separate footing with a slab over. Use ICBO approved anchor bolts, phillips red head or hilti. I prefer the chemical anchors as the wedge type can spin precluding obtaining the required installation torque. Use either.
You will hear that an additional footing is unnecessary and that the lift mfg requires only a 4" thick slab. But if you read the fine print from the lift mfg it also says to comply with local current codes. If you area has adopted the UBC or a version of it, the 4" slab would not comply with codes. Probably a 4" slab would not comply with any code in the US. I expect a lot of guys here might, and on garage journal will, dispute this and those with already installed lifts on 4" slabs will likely verge on the obnoxious in their objections. FYI, The two post lifts not only place a point load on the base but a substantial bending moment. In any case you are the one under the lift so do what you want.
You should check the footing sizes and reinforcing recommendations with your structural engineer. An architect is not a structural engineer, regardless of what he might claim. Apologies to you architects here that think otherwise.
I suggest that making it bigger might include more than just a foot or two in the exterior dimensions. If you have the space and money add another garage bay in addition to the additional 1-2' per side. Consider space for your tools, garden tools, auto tools, and spare parts bins. I have a lot of these bins myself. I have never, ever, heard anyone complain that they have too much garage area.
On the garage floor consider a thicker than the typical 4" thick slab on grade. Often a 4" slab design results in an installed 3" to 5" thick slab because the grade prep is not perfectly level. I have never used the suggested fiber reinforcing but if you do use it,it should not take the place of steel reinforcing. And the reinforcing should be as much as you can tolerate. If you can see your way to #4's at 12" OC EW do it. This will also help with crack control. The contractors don't like 12" OC spacing because they can't fit their boots between the bars. If you do use 12" spacing have them install a lot of dobies to preclude them from forcing the bars down to the bottom of the slab by stepping on them. Have the contractor saw cut some control joints; spacing should be less than 10'.
If you want a lift, the two post kind, I suggest that you scoop out some subgrade and create a large footing centered under the lift posts. Pad footing size would depend upon your lift size and lift capacity. I would create a minimum 5' square, 12" thick pad footing under each lift column. Use #5 bars at 12" OC EW 3" clear from the bottom. Pad footing can be monolithic with the slab or placed separately. The thickness should be at least 12" even if a slab is place over the top during a subsequent pour. Lift post base plate anchor bolts should be installed such that they extend the mfg requirements for embedment into the footing. The AB embedment depth would be different between the monolithic footing-slab pour and the separate footing with a slab over. Use ICBO approved anchor bolts, phillips red head or hilti. I prefer the chemical anchors as the wedge type can spin precluding obtaining the required installation torque. Use either.
You will hear that an additional footing is unnecessary and that the lift mfg requires only a 4" thick slab. But if you read the fine print from the lift mfg it also says to comply with local current codes. If you area has adopted the UBC or a version of it, the 4" slab would not comply with codes. Probably a 4" slab would not comply with any code in the US. I expect a lot of guys here might, and on garage journal will, dispute this and those with already installed lifts on 4" slabs will likely verge on the obnoxious in their objections. FYI, The two post lifts not only place a point load on the base but a substantial bending moment. In any case you are the one under the lift so do what you want.
You should check the footing sizes and reinforcing recommendations with your structural engineer. An architect is not a structural engineer, regardless of what he might claim. Apologies to you architects here that think otherwise.
#32
Rennlist Member
Thread Starter
wow thanks! keep it coming.
im just going to print this thread and give it to my architect/builder since I don't understand any of it lol
im just going to print this thread and give it to my architect/builder since I don't understand any of it lol
The following users liked this post:
911Vintage (06-30-2020)
#33
David gave you great advice, we did use Fiber in our pour and we poured 6 inches, we also slow cured underwater for 30 days and had control joints cut it every 8 feet, I have not had a single crack although all concrete will eventually crack it’s a matter of w David gave you great advice, we did use fiber in our poor and we poured 6 inches, we also slow cured underwater for 30 days and had control joints cut it every 8 feet, have not had a single crack although all concrete will eventually crack it’s a matter of when...
if you need heat, go with heated floors and have an engineer do the calculations, best way to heat in my opinion
I think we poured between eight and 12 inches for our pads for the lift, it’s your life on the line, don’t sacrifice, overkill
if you need heat, go with heated floors and have an engineer do the calculations, best way to heat in my opinion
I think we poured between eight and 12 inches for our pads for the lift, it’s your life on the line, don’t sacrifice, overkill
#34
Rennlist Member
David gave you great advice, we did use Fiber in our pour and we poured 6 inches, we also slow cured underwater for 30 days and had control joints cut it every 8 feet, I have not had a single crack although all concrete will eventually crack it’s a matter of w David gave you great advice, we did use fiber in our poor and we poured 6 inches, we also slow cured underwater for 30 days and had control joints cut it every 8 feet, have not had a single crack although all concrete will eventually crack it’s a matter of when...
if you need heat, go with heated floors and have an engineer do the calculations, best way to heat in my opinion
I think we poured between eight and 12 inches for our pads for the lift, it’s your life on the line, don’t sacrifice, overkill
if you need heat, go with heated floors and have an engineer do the calculations, best way to heat in my opinion
I think we poured between eight and 12 inches for our pads for the lift, it’s your life on the line, don’t sacrifice, overkill
Even on our driveway we overdid it slightly with the cement. We did fiber, rebar, and a 6" pour for the two driveways. Not a single crack in any of it 10 years later. The other thing we did with the driveway and garages that most builders hate doing because it costs them money but we put down a woven GeoMat for driveways with #4 gravel 4" in top of the mat. The GeoMat underneath the gravel is the key for this to work because it keeps the rock from being pushed down into the mud or dirt when heavy trucks deliver the materials for the job. At the end you have a gravel driveway that is almost as smooth as your paved driveway will be and there aren't any mud holes to be driven through. The #4 compresses nicely with the heavy trucks because it has #4, #57 and crusher run sized gravel in it. Think about filling a jar with rocks, pebbles, and sand when thinking about the gravel numbers. Then when the cement guys come to pour the driveway they have a solid base to work on. In the 18months it took to build our house we never added more gravel to the driveway and we never had a muddy mess leaving the property. The key here is to do it from the start and demand they use a GeoMat to go under the gravel. One caveat to this procedure is you will need to dig down the dirt enough to be at the correct height for when the driveway is going to be poured. So essentially in ours we had them dig an extra 3" before they put the gravel down for the driveway and the garage area.
#35
So Im going to check with the city if Im allowed to go beyond the setback with a car elevator into a basement if the basement is underground. See my crude mock up. You drive up, take the elevator down with the car with enough room for tandem parking and about 8 feet on the sides for storage etc. Im encroaching the set backs but everything is underground. Curious to see if the city will allow this. Any architects/builders wanna comment? This is a better idea than trying to put a basement under my house.
#36
I built a new 20' by 45' four car garage last year..We made the floor from top grade concrete to a depth of 6''..Despite by insistence on wanting fibres my builder advised against it..His reasoning was as i wanted a perfectly smooth power floated floor the fibres would prevent this. I went this his advice and so far no regrets.To prevent cracking we just band saw expansion joints every 15'.
#37
#38
If it doesn't work in the space Im thinking, architect is going to look into tunneling under the house- under the garage- he says he has done this before- that will raise the cost but honestly I dont think I want to mess with the foundation of the house that way.
lets see what happens.
#39
Rennlist Member
Actually spoke with a contractor and my architect. Looking into setbacks and such around the house. Basic basement is about $40/foot but mine will be a bit more complex if I can do it so closer to $60/foot- but then tiles, decorations lighting etc. If Im allowed to do this in the place I want with the city and the HOA, looks like about $100/foot so about 100k which I can totally live with.
If it doesn't work in the space Im thinking, architect is going to look into tunneling under the house- under the garage- he says he has done this before- that will raise the cost but honestly I dont think I want to mess with the foundation of the house that way.
lets see what happens.
If it doesn't work in the space Im thinking, architect is going to look into tunneling under the house- under the garage- he says he has done this before- that will raise the cost but honestly I dont think I want to mess with the foundation of the house that way.
lets see what happens.
#40
No go on my idea. The basement as drawn is in the setback which the city wont allow. The only option is going under the slab by digging a basement under the garage which just doesnt sound like fun. Not a project I want to do to compromise the integrity of the house. Looks like I have to find a solution to modify the existing garage. Or build a new house. bummer!
#41
Burning Brakes
FWIW....I did dark brown stained concrete v epoxy paint or Racedeck type tiles.... aesthetically looks good.
If I drop a "one of a kind screw" etc....it disappears.
Big mistake.
________________
'15 991TT
If I drop a "one of a kind screw" etc....it disappears.
Big mistake.
________________
'15 991TT
#42
Rennlist Member
Digging under your garage can be done, but wouldn't make a lot of sense cost wise. Go find another lot down the road..... . Yes, I know that is not easy either! Maybe you could buy a few feet of property from the neighbor and move the easement and property lines? Lots of paperwork, but can be done sometimes. We usually do this once about every 3 years when one of my employees puts a house over the property line.....
#43
Digging under your garage can be done, but wouldn't make a lot of sense cost wise. Go find another lot down the road..... . Yes, I know that is not easy either! Maybe you could buy a few feet of property from the neighbor and move the easement and property lines? Lots of paperwork, but can be done sometimes. We usually do this once about every 3 years when one of my employees puts a house over the property line.....
#44
Rennlist Member
Sounds like a worthwhile project. I wanted to move and build again, but my wife put her foot down. Been married 26 years and she has lived in 10 houses and this one is the longest (5 years). I see all the newest gadgets of course being in the industry, so I start jonesing for a new house every 3 years. Since she said no, and there is no lots in my neighborhood, I decided to build the detached garage and remodel a few things I don't like. My problem is my youngest is 16. So she won't consider moving until he is out of the house. PV is where I would like to bet as well with a big garage on a 2 acre lot. Need to wait for a downturn though to buy the land since it is way overpriced.
#45
Sounds like a worthwhile project. I wanted to move and build again, but my wife put her foot down. Been married 26 years and she has lived in 10 houses and this one is the longest (5 years). I see all the newest gadgets of course being in the industry, so I start jonesing for a new house every 3 years. Since she said no, and there is no lots in my neighborhood, I decided to build the detached garage and remodel a few things I don't like. My problem is my youngest is 16. So she won't consider moving until he is out of the house. PV is where I would like to bet as well with a big garage on a 2 acre lot. Need to wait for a downturn though to buy the land since it is way overpriced.