# Carport Conversion - wall footer issue



## cybercelt (Oct 5, 2005)

We are planning to convert a carport into a room (livable space). It currently has 2 full walls (exterior walls of the house), a finished ceiling, and a 1/2 block wall on the outside (not attached to the house walls, but with posts to the roof. This is presumably a 'bearing wall'. 


Our plan is to frame with 2x4s the front open area (where you pull the car in), add siding (like T1-11), insulation and drywall. On the side with the 1/2 block wall, we plan to add framing (2x4) on top of the wall to the roof, maybe some furring stips on the inside of the wall, then insulate, drywall, and 1/2 siding (on top of the wall)



In my first attempt to get a permit with the city, they asked for more detailed 'cross section' drawings of how we will do the framing, especially on top of the block wall, and including the footing underneath the wall. It doesnt have much of a footing right now, maybe a few inches deep. It seems that adding some framing and windows is not much weight for a block wall to hold, but contractors I spoke to claim we have to knock down the wall, add a footer and then frame.



Is that really necessary? It seems like a real waste of energy if the block wall can hold some wood weight. Also, the thought of taking down those bearing posts makes me worry that the roof will fall down (even with their 'temporary bracing'). He also claims we have to raise the floor (but I know it's not necessary for livable space and it's already 3-4 inches above the dirt line)



I'd like to hire a general contractor, but I know that I'll rarely see them at the house, but instead will see their hired help, and their prices all seem quite a lot. I estimate materials to be about $2500 - $3000 if we do it ourselves (we'd hire an electrician for all electrical work), but the quotes are coming in at 10-12k. Do contractors really get 7-9K in labor and markup on this kind of thing?


Any feedback is appreciated. 


CC


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## mighty anvil (Oct 5, 2005)

It's not possible to give you advice without knowing where you live and what the building code foundation requirments are. In the absence of that information I would suggest you take the advice of the contractors and the building inspector since you are obviously dealing with somethng you know little about.


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## cybercelt (Oct 5, 2005)

"It's not possible to give you advice without knowing where you live and what the building code foundation requirments are."

Phoenix, AZ - Do you know what the standard building code is regarding this issue and/or what any possible phoenix arizona variance is?

" In the absence of that information I would suggest you take the advice of the contractors"

It was only one contractor and only after I said the city asked me to show the framing and footer (he, the city permit employee, did not specify how big the footer had to be)

and the building inspector
no building inspector said that it was necessary

since you are obviously dealing with somethng you know little about
Thank you. 
That's why I'm in this forum, I'm trying to find out if this is true or if this one contractor is just trying to make a lot of extra money by doing unnecessary work. The last contractor I hired (to put in a new patio door), ended up committing credit card fraud against me after he was done. Just because someone has a contractor's license does not make him honest, only more liable for dishonesty (theoretically). I would like to hire a contractor who knows what he's doing and that I trust. Anyone know someone who qualifies in Phoenix?


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## mighty anvil (Oct 5, 2005)

If the roof is already properly supported by posts with foundations you don't need much to hold up non-bearing stud walls but you must have a continuous footing and it must be placed below the frost line (ask the building inspector for that depth) The code will probably set a minimum footing width as well. Perhaps the one you already have will be ok since the load is so light. You will have to add one where the car enters now. A few inches above grade is not ideal but I suppose it will work if there is no requirement for minimum height above grade for wood framing. Here in Boston it is 8" unless it is pressure treated. Is there is an existing level concrete slab?


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## K2eoj (Aug 14, 2005)

Probably no frost line in Phoenix?? You might check to see if you can find a local building consultant. One visit and 10 or 20 phone conversations might get you straightened out. Also a local architectual student might have fun helping you.


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## cybercelt (Oct 5, 2005)

*Footing & Slab*

Yea, I dont think we have a frost line issue here, we nearly melted this summer. 

I did some light reading last nite of the uniform building code (which is almost as exiting as the tax code!), but it's still difficult to find out this issue because it's a 'conversion' (meaning the rules seem to tell you how to build things with their original intentions, but not if you want to change it to something new, like an 'accessory' wall becoming an 'exterior' wall.) ugg.


I measured 8" of what appears to me to be wall/concrete below the dirt line today. However, most of it (7.5 inches) was the same width as the block wall, with the very bottom have a small lip outward (about 1"). Is that considered a footer if it is mostly the same width as the wall. Also, it's possible that this is the whole house foundation and not just a footer under a wall. The carport floor is raised 6 inches above the dirt line, plus I'd be happy to use pressure treated wood.

I agree that it could not be much weight to add some studs, windows, and siding. Hopefully the 8" bottom of the wall will be sufficient.

I'd like to ask a building consultant, I thought this was too small of a job, but I'll see what I can find.

Thanks for the feedback.




hammerslammer said:


> Probably no frost line in Phoenix?? You might check to see if you can find a local building consultant. One visit and 10 or 20 phone conversations might get you straightened out. Also a local architectual student might have fun helping you.


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## mighty anvil (Oct 5, 2005)

Where soil has good bearing capacity, a foundation wall doesn't have to be wider than 10" but they are usually 16" or wider since it is cheap insurance against settlement.


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## K2eoj (Aug 14, 2005)

Mighty, disagreement here.Commenting on soil bearing from 2000 miles away will only confuse this person and waste their time. Since you are an Architect you certainly know about expansive soils that would totally change the design. I don't know if there are expansive soils in AZ. but it sounds like you don't either since you were talking about frost in Phoenix. Cyber needs to find a local either on line or in person to help them. A carport conversion is probably more complicated than new addition because the rules are open to interpretation. HS.


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## mighty anvil (Oct 5, 2005)

I advised cybercelt to check the frost/foundation depth requirement because, although I have not built in Phoenix, I know that the frost/foundation depth is 12" in Tucson which is farther south. A 12 or 14 inch depth requirement could cause cybercelt to have to tear down the carport in order to build the addition. It seemed to me that finding the actual depth requirement would be the best place to start rather than soil bearing capacity.

The building code will not be interpreted differently just because the structure already exists. If cybercelt is changing the use of a structure, or any part of a structure, from uninhabited to inhabited, it must meet all provisions of the current building code as if it were new construction unless cybercelt gets an engineer to state that the structure is effectively equivalent to the code requirement or gets a code variance.


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## Teetorbilt (Feb 7, 2004)

Let's look at the facts. The carport has been in existance for years, that pretty much eliminates the frost question. It was designed to hold cars and support the roof overhang, that pretty much eliminates the structural aspects. I don't understand the hubub.

Enclosing carports here is a fact of life in most of the older subdivisions (carports were most common here from the 40's through 60's). I have never heard of any structural problems in enclosing them.


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## K2eoj (Aug 14, 2005)

Sounded like Cyber's building dept had some issues. There would be some issues with a conversion like this with my local dept in addition to frost. HS


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## mighty anvil (Oct 5, 2005)

Teetorbilt, you are assuming that the building department will accept the existing carport structure as exempt from the current building code even if it is nonconforming. That might happen but I doubt it because the necessary changes to the structure are so great and the existing structure seems to be substandard and the building department has already asked for existing footing information.

The building code in Phoenix is the 2003 International Residential Code with amendments. It is available online:
http://www2.iccsafe.org/phoenix/Phoenix_IRC/residential_frameset.htm

The minimum depth below undisturbed grade for footings is 12". 
The minimum width of footings for1-story wood frame or masonry wall construction is 12" (16" where soil capacity is as low as 1500 psf with a masonry wall) 

Cybercelt needs to dig down far enough to completely expose the footing that is there, then take that information to the building department and see if they will accept it. Of course, all new construction will have to meet the requirements of the current code.

By the way, expansive soil would not change the design of the footing. This kind of material, like organic material, is unsuitable for bearing and would therefore be removed and replaced with a suitable granular fill. The only variable in footing design is if the building inspector asked for a soil test and it turned out to be below 1500 psf which seems unlikely given the condition of the existing structures.


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## K2eoj (Aug 14, 2005)

Mighty, Good post! >> We have 3 or 4 ways of dealing with expansive clay but that is a subject for another thread another day. HS.


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## cybercelt (Oct 5, 2005)

Hi Everyone...
Wow, it's interesting to see all of you talking about this.

I did dig down to the bottom of the footer, it is 8" below the dirt line, but is completely flush with the wall itself, except for the very bottom 1/2" which is about an inch out. I dont know how wide it is because I cant see the other side (it's underneath the carport floor.)

BTW, I tried to include a photo here, but the size requirement is so small, I couldnt fit it. So, if anyone is interested, I posted it to my yahoo photos at http://photos.yahoo.com/cybercelt19. Look in the Album called "Carport".

I am going to try to find someone to hire to at least just do the design, but contstruction has gone wild here, and people aren't interested in 'small' jobs like this.

thanks



hammerslammer said:


> Mighty, Good post! >> We have 3 or 4 ways of dealing with expansive clay but that is a subject for another thread another day. HS.


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## mighty anvil (Oct 5, 2005)

Since the existing roof is held up by posts you should dig down and see what is under them. If there is a deeper footing there you might get the building dept to allow the 8" deep footing under the non-bearing walls between the posts.


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## cybercelt (Oct 5, 2005)

FYI, 

I did more digging and discovered that there is a 12" continuous footer along the whole way (the 8" footer I thought I saw was actually a place where the dirt was lower and so it was actually 12"). I had a contractor draw up more of the plans to supplement what I had done and our permit was approved by the city. Yeah!

Now we have to get to work.


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## mighty anvil (Oct 5, 2005)

Good work Cybercelt, good luck with the construction phase.


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## Teetorbilt (Feb 7, 2004)

Anvil, I tend to forget the rest of the nation where a carport could be an independent slab with an attached overhang. Here, most carports are an integral part of the structure, often sharing a common slab and roof.


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## cybercelt (Oct 5, 2005)

*Passed Pre-Drywall Inspection*

We just passed the pre-drywall inspection on Thursday and got the siding up on Friday. We're using individual tongue and groove instead of T1-11, so it's more work and more expensive in materials, but it looks nicer IMO and matches another area of the house.

 

We should be finished next week.


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## mighty anvil (Oct 5, 2005)

Send us a photo.


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## cybercelt (Oct 5, 2005)

*Photos*

The files are too big to attach to a message, but you should be able to see them here:

http://photos.yahoo.com/cybercelt19


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## 747 (Feb 11, 2005)

Tongue and grove carsiding that will work. My dad built a toolshed out of that back in the early 70s its still standing strong.


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