I have what seems to be a unique situation (I can't seem tofind any info on it anywhere!).  We recently bought a house 405 yrs ago anyway.  The house is about 15 yrs old.  The problem started when we discovered that our window frames seemed to be rotting.  We took them off in an attempt to replace them....

We found out the SIP panel is rotten.  We checked around and this seems to be the case in several places.  The exterior wood on the panel is rotten.  How on earth do we correct this?  We cannot ignore it and replace the window frame as there isn't anything to attach it to.

Do we scrape off all the pressboard type exterior of the SIP and glue on new?  Do we have to replace the entire SIP panel (that may end up being almost our entire house!)  Any ideas if this would be covered under our home owners??

Advice from anyone who has experienced this or is a professional and has seen this would be greatly appreciated!!!!

TK;

If the rot doesn't go back too far, you can cut out bad OSB and the foam to install solid wood studs/backing, glue and screw in place fill any voids withspray foam.

You had better check all flashed areas for damage and properly install new flashing

We will have to start taking off the siding to check into this further. What I am afraid of is that it is well beyond the window frame and that much of the OSB on the panel is rotted. If this is the case, what are my options?

Tk you shoudl do some research and find who the manufacturer is, most of them will warrant there product and if not should be able to tell you what you need to do to get it repaired.

TK;

You still need to remove the siding to assess the damage, I don't know of any mfg. that will warrantee for improper flashing, Being 15 years old you are pretty much on your own

We will do that. I do believe it has proper flashing but hey who knows what we will find when we remove the siding! Anyway, I didn't think the manufacturer would cover this. I am more concerned about the insurance company covering it! AND how to correct it?????

If it was properly flashed we would not be having this discussion?

Mute point... I won't know till I take off the siding. The real issue here is how to correct? Obviously proper flashing will be needed when correcting but the correction part is key to this whole thing... What do I do for the panels? Is it possible to correct large areas of rot on a SIP panel? What if the whole board is rotted? I heard a rumour that the previous owner didn't side the house till right before he sold it. If this is true I have a BIG problem on my hands. I will further investigate....but what are my options on correcting it?

TK;

I just sent you an email. I have some suggestions for you.

SIP panels do lend themselves to replacement more so than conventional stick construction, but it can be a big job depending upon how widespread the problem is. Where are you located? I may know someone in your area that can look at it and give you the alternatives.

You might have less of a problem then you think with the previous owner. You might spend your time first doing some investigating. Put your real estate agent on it. If the siding was not done with flashing and if it was delayed in getting installed properly then the previous owner had a responsibility to disclose that it the sale. If so you should get an attorney and start going after people. You might find liability in the insurance companies and title companies having some responsibility on both sides of the transaction. So perhaps you can get all of your problems paid for. And make sure you document all of your time in the process as it is an expense.

You can always cut out a window and stick build a section for replacement. You would cut back the SIP until you have no issues and recess as an end panel on each end. Insert stud and then stick build a window section to replace the damaged portion. This is a pretty easy fix and makes more sense if getting a couple of SIP panels will create a lot of expense. This would also eliminate the need for engineering as sticks are prescriptive and you would just have to build a regular stick header.

What part of the country do you live in TK?

K.

I worked on a timber framed house with stress skin panels; (similar but non structural) where some OSB had rotted due to poor flashing details.  We cut away the bad OSB from the foam, cut a replacement piece of OSB & fastened it to the spline where possible.  Where that was not possible we chiseled out some foam, made up a spline & screwed that to the good OSB & to the patch.  As I said this was NOT a structural houses so there were no support issues.  Most of the foam was in very good shape, where there were any voids we filled with spray foam.
Might work in a small area with SIPS but it would be prudent to check with a structural  engineer. 

Worked on another timber framed house years ago where the roof OSB had disintegrated, probably due to poor installation practices by the company which by then had closed.  After scraping the remaining wood off the foam we strapped the roof with 2x4s fastened to the timbers, another layer of "vertical" 2x4s for venting, plywood & shingles.

Bob Irving

TK,

Your last post you said it was a "mute point".?! Is this a point brought up by a mime or did you mean the term "moot point" that has two meanings, 1. a point worth discussing at a meeting (or in court)—an unresolved question 2. a point already settled and not worth discussing further.

ICF Contractor

Interesting discussion and one that focuses on our main concern. We are considering SIPS now for a larger (9800 sq ft home) and have serious concerns about OSB, water etc. One thought was to use Avantech (sp? a water resistant plywood) instead of OSB. I was told that Insulspan would do so but the dimensions of the panels are limited to 4x8 because of the plywood. Any and all thoughts are appreciated.
Q. Am I overly concerned with OSB? (once wet ruined)
Q. Does the plywood solve any of this? i.e. if water intrusion monitored and stopped then plywood can return to close to its original dimensions
Q. There are limited resources in central Indiana for ICF construction. any answers on this one?
Q. What structural techniques would you use if you were building that "last home for retirement for the next 35 years or more.

Richard;

Avantech is available in bigger sheets, probably the same as OSB, if you read the posts on the rotten OSB you will see that the house was 15 years old and so it was not a matter of getting wet once, more than likely this was an ongoing flashing problem for many years that just went un-noticed by the owner until it came time to replace a bad window
Plywood will rot the same as OSB under the same contitions.
It is as I have stated before - one of the reasons I made the switch from OSB to galvanized steel panels was the potential for rot or mold if a tiny leak goes un-noticed for years. They are also termite/ mold resistant. lighter in weight, more uniform in size, hurricane impact resistant, available in longer lengths.
It is what I am building with for my "last" house as I do for many others.

Did you see my comments to this question in the ICF forum?