Pouring Concrete Slab For Porch

Old 08-18-18, 05:42 PM
Thread Starter
Join Date: Nov 2015
Location: USA
Posts: 29
Upvotes: 0
Received 0 Upvotes on 0 Posts
Pouring Concrete Slab For Porch

Hello, we are considering installing a concrete foundation for a new porch. We are thinking about going with 16' x 20' or something like that. We have an existing patio foundation that I figured we would need to jackhammer and remove. Can someone tell me if sometimes better to expand an existing patio or jackhammer it and build all new? Our existing patio is about 10' x 10'. It just seems like if try to expand existing patio, might have issues with not knowing how the patio is currently tied in with existing foundation, not knowing how thick the patio is and if would support adding on a room, etc.

Also, I would like to compare costs for building a patio foundation that would be suitable for adding onto the house, which is a one-story house, or suitable for some kind of porch covering with walls open, or just simply a concrete patio with no walls or roof.

Our city's building permit website says they go by the International Residential Code. Does anyone recommend some alternative, detailed specifications that are more in layman's terms and you don't need a lawyer or doctor's degree to understand? This information would include width and depth of concrete footings, soil preparation & vapor barriers (if applicable or necessary), method of installing steel rebar and method of tying in rebar to existing foundation if decide to go with home add-on foundation versus simple patio.

Another good thing to have would be good estimates of cost whether doing myself of hiring it out to someone else and maybe recommended contractors in the North Dallas Texas area if decide to hire it out.

Old 08-18-18, 05:46 PM
Tolyn Ironhand's Avatar
Group Moderator
Join Date: Nov 2007
Location: United States
Posts: 14,481
Received 913 Upvotes on 771 Posts
If the porch is attached to the house you will need to install footings that go past the frost line in your area. The foundation will then be built on top of the footings.

Best thing I can recommend is to come up with a good drawn plans which you can show contractors, lumber yards, and permit departments. That way you will be talking apples to apples with everybody.
Old 08-19-18, 05:29 AM
Marq1's Avatar
Join Date: Sep 2016
Location: USA MI
Posts: 9,745
Received 1,211 Upvotes on 1,099 Posts
As you noted there are a lot of unknowns and that will be something you need to resolve, also what it will be used for makes a huge difference in how it is constructed, plus the aesthetics of new and old concrete.

Concrete is one job I simply will not do outside of a very small pad, it;s a HUGE job mixing concrete and trying to do that at a pace to keep the pour going.

Plus you still have to haul all that cement home and it;s incredibly heavy, let those young kids have at it.
Old 08-19-18, 05:57 AM
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 28,324
Received 2,310 Upvotes on 2,055 Posts
Since you are "opening up" the area all work, old and new, must comply with code. Whether or not you can expand your existing patio depends on whether or not it is up to code. If it does have proper footers that meet code then you can keep it and expand on it. If there are no footers or they are not up to code then the old will need to be removed.

As for translating the code for you we can help you with specific questions but we can't Micky Mouse it for you. There are numerous websites and images online that show various interpretations of the code. But the devil is in the details. What you must do depends on your site and since we can't see what you've got we can only help so much. But, if reading and understanding the code is too much then I suggest hiring the work done by a professional.

Thread Tools
Search this Thread
Ask a Question
Question Title: