Bathroom Addition

[AlexSwansboro]

My wife and I are considering a bathroom addition that would be about 10'x10'. It would be right next to the master bedroom and would also butt up against a porch. The mast bedroom is on a traditional foundation and the porch is on cinder block pilings. In the interest of saving money I am going to do the electrical, and most of the interior work. I am also going to be GC. My question is about the foundation. I know that the way I do it depends on local codes etc. however, is there a reason that I need to have a cinder block foundation going all the way around the addition perimeter? I already have the traditional cinder block foundation on one side and perpendicular to that I have the cinder block pilings. I'm thinking that I just need 1 more foundation wall parallel to the porch wall and perpendicular to the existing house wall.

Your thoughts would be much appreciated.

 

[mkepke]

Its hard to visualize exactly what you mean by "I just need one more foundation wall parallel to the porch wall..." - can you share a sketch ?

But if you are asking do you need a continuous cinderblock foundation, I think the answer is no unless you have a very unusual building code in your area. The existing cinderblock pilings are *probably* strong enough for a 1-story addition, but this would need to be verified/inspected.

From high cost to low cost, I think your foundation-wall options are:

a continuous foundation with poured concrete stem walls
a continuous foundation with cinderblock stem walls
a continuous foundation with wood (stud) stem walls
a pier foundation

A couple comments: I would take resale value into consideration when deciding which way to go here. A pier foundation will look cheap if the rest of the house is say parged cinderblock. As mentioned, the existing cinderblock piers may be considered structurally inadequate to support a living space above. And with the 'crawlspace' exposed on one side, the plumbing is more susceptible to freezing and the HVAC to energy loss.

FWIW, I am considering something very similar by expanding my house's living room footprint (continuous brick and cinderblock foundation) to consume some space currently occupied by a deck (on brick pilings). I would like to dig out the space to a livable basement height and use the resulting small basement as a combination of hurricane/tornado shelter and storage.

-Mark

 

[Skymaster]

IMHO for efficiency sake, enclosed is waaaaay better, also keeps critters out of your wiring,plumbing,insulation. closed space is more even temperatures. easier on heat and a/c bills, plus if it is high enuf, a nice dry enclosed storage place

 

[AlexSwansboro]

Above you will find a drawing of my house and the issues I am considering. I'd like the have to build only 1 solid foundation wall as shown as I am concerned that I have to do two walls (I am assuming I won't need a foundation for the porch as it already has one and I just tie into it) one of which would run near the in ground gas tank I might have to remove the tank and re burry it. I am looking to do this as cost effective as possible and I even have a hot tub that I'm willing to trade for some help, materials, labor etc.

Any advice you can provide would be much appreciated.

 

[chris_goris]

In my opinion, a foundation is NOT an area to skimp on. Just my $.02.