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View Full Version : Attach porch roof to brick veneer?



tommyboy
12-03-2007, 05:04 AM
I have a client that used to have an awning attached to a walk-out basement door. It has blown off a few times due to wind and they want we to build a small porch roof (covering a 6x8 area) over the door instead. The problem is that the house is in brick veneer (full brick). I was planning on a hip roof for strength against wind and also to eliminate the need to cover a gable with a material that won't be brick. Any ideas on the best way to attach the 2 small rafters and 1 longer (5'?) nailer for the rafters running into the house? Also, should I try a gable roof instead to eliminate and load against the house?

Thanks for any suggestions,
Tom

Jordan
12-03-2007, 05:58 PM
Code prohibits attaching any loadbearing member (both lateral and gravity) to any masonry veneer. You need to find some way to tie into the structural wall beyond. Normally, this is done by placing a new lintel and removing a couple courses of brick so that a ledger can be placed directly on the wall. If just the simple ledger is placed (it will need to be a 6x8 or similar, due to the veneer thickness), then you have to sheathe the ceiling of the roof so that the lateral shear has a path to the building's main lateral force resisting system. You could place posts at the veneer wall, but that won't solve the lateral force issue. In critical conditions, I've put in two long 1" threaded rods at 90 degrees to one another and 45 deg to the house (making a triangle with two rods and the wall) using epoxy and screen tubes into the CMU backup.


Or you can use tapcons like eveybody else and call it a day, and let the next guy fix it.

TSJHD1
12-03-2007, 06:24 PM
Or you can use tapcons like eveybody else and call it a day, and let the next guy fix it.

Its a tiny 6x8 roof. Half of its load would be on posts probably. What kind of loads could it possibly place on the brick? You saying that a new home, say 2-story brick veneer, would need some sort of special connection detail to attach a simple small entry shed roof?

I can't see it being an issue, but I don't know the code specifics for something like that.

I'd check with the building inspector, but I think attaching a pressure treated ledger with tapcons and construction adhesive would be acceptable. But maybe this is another one of those situations on a house where it has to be overbuilt to be considered right.

Tom

WarriorWithWood
12-03-2007, 06:41 PM
I have a couple of questions:

Is there a roof above this porch? (or is the roof pitched toward the porch)
I used to think the same as you, until the inspector told me that you have to consider the upper roof snow load into it in case the snow slides off.

Are you going to put a load bearing half post against the brick?
I think this would help, then all you have to figure is the pull out strength.

These are just a couple things that popped into my head when I read your post.

John Ellis
12-04-2007, 01:31 AM
I don't think being able to park a truck on top of this thing will ever be an issue so..........the cost of this replacement "awning" should not be up'ed just to relieve a structural engineer's calculations of hurricane force winds with 42 psf snow load( seriously???) Notch out your brick veneer 3 1/8 " x 9 3/8 and slide a couple of 2x10's in the holes. Run a ridge board or rafters against the veneer with some anchors and glue (Ice and watershield behind would help) and sheet it and it will last for many years, I would say at least 20. Unless a tree falls on it.....or someone thinks it's an atm machine and puts a chain around it and pulls it of with a pretty big truck! Besides the sarcasm, I hope this helps.

BeachBoy
12-04-2007, 02:19 AM
Can you design it so all of the support is from posts? (Same thing as building an independant porch rather than hanging it off of the building.)

tommyboy
12-04-2007, 04:55 AM
I can make it a gable roof and all load would be on the posts. I just wanted to fasten it to the veneer just to hold it it place. There is no roof above it where snow would be sliding off on to the little roof. I just wanted it to be safe and not give the owners any trouble. The attachment points are just so the whole porch doesn't fall off the house. That's why I was "leaning" toward a hip roof. Personally they should be building a small room there instead of just a roof, but they are on a limited income and just want a replacement for the awning.

Thanks for the suggestions!
Tom

rpadgett
12-06-2007, 01:32 PM
I think what Beachboy meant was to use 4 posts, 2 on the outside corners, and 2 against the brick veneer, that would actually support that end of the rood structure.

Is that right BB?

BeachBoy
12-07-2007, 01:36 AM
Yes, that is correct.

Jordan
12-07-2007, 03:36 PM
Its a tiny 6x8 roof. Half of its load would be on posts probably. What kind of loads could it possibly place on the brick? You saying that a new home, say 2-story brick veneer, would need some sort of special connection detail to attach a simple small entry shed roof?
<snip>
Tom

Yes, that's the way the code is written. The connections for brick venner are not meant to withstand additional forces. Sure, they will, which is why many people just tapcon in a ledger and let fly. But if your code inspector knows the book and wants to be a pain about it, they can make you tear it down and build it again. I don't really see it as much of an issue under normal conditions, but code says I have to design for a 50 year event. If you build it this way a hundred times, it may only cause problems in two or three installations (provided you did all your flashing correctly).

*shrug* It's not my project so it's no matter either way to me. Besides, I make good money writing reports on how things were done "wrong".

tommyboy
12-07-2007, 04:01 PM
Will there be a downward load?... I am putting posts against the house and out at the corners to support the doubled up 2x10 beams the rafters will sit on. I'm thinking the only loads will be either pushing into the brick (w/ a hip roof) or push/pull with a gable roof.

Joe Carola
12-07-2007, 04:20 PM
Will there be a downward load?... I am putting posts against the house and out at the corners to support the doubled up 2x10 beams the rafters will sit on. I'm thinking the only loads will be either pushing into the brick (w/ a hip roof) or push/pull with a gable roof.

Tommy,

Why do you need posts against the house? You can notch the brick and slide the small header in on top of the brick.

houseboy
12-08-2007, 08:34 AM
To pick up on the point jordan made, the code says one MAY NOT bear on the veneer and lateral loads (such as those which would occur in holding the porch roof in place laterally) may not be applied to the brick. Now, everybody seems to agree that this little porch roof will not be a significant problem (probably).
My questions are:
At what point (or what size of porch roof or deck structure since wood deck structures are commonly attached to brick veneer this way) is the appendage sufficiently large so that one would agree that the forces on the brick ARE too great and the provisions of the code SHOULD be followed? In other words, where do you draw the line?
One poster doesn't see the need to "relieve the strucural engineer's calculations". It sounds like there are two standards, one for which "probably" or "usually" or "in the opinion of the builder" (presumably a high quality builder) there is not likely to be a problem, and the other for which the construction IS in compliance with the code.
My experience is that some owners would be uncomfortable if they knew that the construction did not really meet the code. Now, maybe they can accept it if it means a cost savings. I understand that motivation. The problem comes in on those few occasions when there is a problem.
Who agreed to accept sub-standard construction?
How well did they understand the risk they were taking?
Who in the process SHOULD have been knowledgable about the code requirements (the owner or the builder)?
Who is willing pay for the repair?
I think as jordan implied, we all know that "it" happens all the time. To my way of thinking, I think it's important that the person who is taking the risk should be the same one who is realizing the cost savings AND should understand what they are getting or not getting in teerms of code compliance.
I've heard it argued that owners would not buy something if they understood all the risks they were assuming. Shouldn't that tell us something?
Please don't everybody get all work up over this post. I just know a few engineers who make a good living picking apart these little trangressions of the code....