Ok, So I went ahead and decided to purchase a 2004 built home with 6" ICF Nudura used both on the foundation and the walls. - The roof however is a regular one, insulated with cellulose and wide open to the attached garage. I have 2 questions: 1) How can I make the roof stronger, so that I can take advantage of the supposed extra wind resistance of ICFs. - IE: If there's a hurricane, and the roof blows off, there's no benefit to me having ICF walls, I will still die! :) - Is there some product(s) I can buy to brace the roof internally (ie: I don't want those straps on the outside). 2) If I want to add an addition to the house, how hard/expensive would it be? - I mean, it must not be that easy to drill an entrance and cut the rebar through a wall..? Thanks Experts! Patrick

This is a very common practice for additions these days, we are just finishing up a two story with walkout basement on a elder care housing unit. The two factors are sealing the joint between the existing structure and the new ICF, and getting a positive lock between the two structures. Here is what we do 1. because the two structures will most likley move different than each other we cut slots in a treated 2X that is the width of the form the slots run horizontal 2" long and get screwed on to the existing by placing the screw in the center of the slot. Steel anchor have been placed 16" apart (on the vertical) from the back side to allow for a lock into the concrete. Then the wall is poured and consolidation done to insure a positive lock to the anchors. 2. The next issue is sealing the joint with a flexible material so that you do not have any air flow through the joint. This is accomplished by using two layers of sill seal between the treated plate and the existing wall. The next step is to place a seal over the joint on the outside we use a 6" wide tape commonly refered to as window and door flashing and then side over it.

oops sorry Patrick this should have been to the question about adding to and existing wood frame.

Hi Patrick:

Congratulations on being the proud owner of an ICF House -- Good Decision!

Patrick, for the need and strategy for making the roof stronger (reinforcing the roof structure), I suggest you consult a structural engineer and  the supplier of your roof structure -- they will be in the best position to advise you whether it is necessary, and if it is, then what is the best course of action.

Patrick:

When you decide to add, then again you will consult a structural engineer to determine where and how an entrance can be made by saw cutting an ICF wall -- although it is not as easy as it is to cut into a stick wall, but saw-cutting an opening into an ICF wall and providing a header as necessary will not be very hard and will not be very expensive.

Pat,
The State of Florida has a program to help people address this problem with existing houses. You can look at their procedures at
http://www.mysafefloridahome.com/
Basically, you need to take the soffit down so you can get to the top of the wall between the roof trusses. Take a folded metal plate from the Simpson Co or Home Depot place it on top of the wall next to the truss's. Attachment is a problem of course because of the lack of space but you can screw or nail into the truss. The other half of the connection is done with Liquid Nail.
The roof seating to the truss connection is handled the same way with Construction Adhesive and a folded metal strip a foot long a lot like corner bead. Start at the eve and work you way as far up into the roof area as you can reach.
I set a load test using a 2" wide leg on the angle and 12" long to see how much weight it would hold and I had 135 pounds hung off of the strap before it broke.
The State also recommends that you put a 1/4" bead of adhesive along the joint between the sheathing and the trusses but I prefer the metal.
They also have procedures for the joint between the top of a regular wall and the gable end framing but that probably would not apply to your case.
Drop me an email if you have any questions as I am one of the few State Approved GC's that can do the work.
Regards,
Joe

some of my builders use these products, seem to work very well for older structures.... http://www.hurricanefoamseal.com/index.html [email protected] [email protected]

Thanks for the advice folks!  Much apreciated!

Patrick