Concrete patio -- where it meets the house

A friend of mine is adding a concrete slab patio to the back of his house. He has enough experience in pouring and finishing concrete that he is comfortable doing the patio. But, he has a question about where the patio meets the house. The house has a brick exterior where the patio will meet the house, and he is wondering if he should just pour the concrete right up to the house, or place an expansion joint along the back of the house and pour up to that. I don't know the answer but I said I would try posting the question here. His house is in New Jersey in case that matters in terms of climate etc.

On 6/21/2011 6:31 PM, RogerT wrote:
  Quoted Text Here  
Risk of a close-up patio is, that if the patio frost-heaves (and most do, since foundation under house stays warmer), you can get ponding against house after heavy rains, which ends up running into basement, and can sometimes ever build up enough hydrostatic pressure to bow the basement wall, if it has nowhere else to go. Seen it several times as a kid working in the business, and again a few years ago when house-shopping.
But yeah, I always see an expansion joint used. Your friend should make sure their foundation drains work, and make sure patio has enough slope and a good set of footings under it. Maybe even add a sideways drainage slot near the house, headed to a drain tile or dry well under a bush or something. That far north, I would do deep actual footings, not just a 'thick edge' monolithic pour. If there is a chance in hell he will ever want to make it into a 3-seasons room, actual footings below frost line are indicated.

  Quoted Text Here  
I'd think that anyone with experience would know an expansion joint should be there. He should probably check his knowledge of base prep and reinforcement too. All of NJ is in freezing zone and that patio will move.

  Quoted Text Here  
Amen!

Ed Pawlowski wrote:
  Quoted Text Here  
Thanks for the feedback.
I don't know what is correct, but in doing an Internet search it does seem that more often than not people do recommend putting in the expansion joint. I was surprised to also see a number of other options also posted on the Internet that involved tying the patio into the foundation with rebar etc. I don't know if that is a good idea, but it seems a little strange to me. Also, some of the videos I see of professional contractors pouring and finishing a patio do not show either an expansion joint at the house interface or rebar tying the patio into the house foundation.
I do know that my friend is using stone underneath and compacting the base, plus wire mesh, plus rebar, and will be sloping the patio 1/4 inch per foot away from the house. And, he said that when ordering the concrete, he is getting concrete that is called something like "fiber reinforced" (I forget the term) and a higher strength concrete (I forget the "pounds" or whatever it is called).
For those who may be interested, here are some of the links I found when doing an Internet search:

http://www.youtube.com/watch?v=LP8AERpaZk0

http://extras.berkshireeagle.com/Nebe/pool/concrete.html
http://www.askthebuilder.com/371_A_Patio_of_Concrete_-_the_Right_Way.shtml
http://en.allexperts.com/q/Building-Homes-Extensions-2333/Concrete-patio-1.htm
http://www.homekb.com/Uwe/Forum.aspx/repair/46780/Attaching-Patio-to-House
https://advice.thisoldhouse.com/showthread.php?th94
http://www.dependorent-all.com/Tips%20and%20Tricks/Building%20a%20Concrete%20Patio.htm
http://www.renovation-headquarters.com/concrete-patio.htm .

  Quoted Text Here  
I am not sure if the fibre-reinforced concrete is really any better. Our condo association in CO used the reinforced concrete for a patio, and the new concrete cracked within 2 years even though the base was properly compacted, etc. It may just be a selling $$ point.

On 6/22/2011 12:44 PM, hr(bob) snipped-for-privacy@att.net wrote:
  Quoted Text Here  
Issue isn't the slab cracking- patio is light-duty, and nobody is driving on it. Issue is the side of patio away from house lifting when ground freezes. That 1/4 per foot slope can quickly be pointing the other way, and you have a pond by the house. Gravel layer is good, but make sure the water under there has somewhere to go. If it is trapped under there and freezes, it'll lift the slab right up. I still think footers are a good idea.

On 06/21/2011 06:31 PM, RogerT wrote:
  Quoted Text Here  
A new install should have a joint but be aware that the joint must be maintained or water *will* get into your basement. Not to mention sloping it away from the house. If its possible to slope the patio toward a drain your results will be even better. We were able to connect up to a buried 4" drain intended to catch down spout water that runs along the end of the house. Its carried about 60' away from the house along a good down slope.
In snow zones, melting snow is more of a problem than rain. Get the snow off the patio or at least away from the foundation or it will very quickly seep into the joint when it melts.
We poured a third layer (probably close to a foot thick by now) over an existing 40' patio four or five years ago due to repeated moisture problems in the basement. Unlike the other two layers it was poured directly against the brick this time. Since then the moisture problem has gone away and there is no sign of bowed walls. Brick over concrete block is pretty sturdy but only a really-really thick sub base made this practical.
From SW Pennsylvania,
John

  Quoted Text Here  
Thanks. I passed on your information and the other feedback to my friend. He said he will be using an expansion joint.

  Quoted Text Here  
Thanks. I passed on your information and the other feedback to my friend. He said he will be using an expansion joint.

  Quoted Text Here  
Thanks. I passed on your information and the other feedback to my friend. He said he will be using an expansion joint.