I am looking for information conscerning the repair and moisture mitigation of the SIP's on my roof.  I was in the process of having my roof re-shingled when I found extensive water damage on the outer skin of the sips.  I am not sure if the damage was caused by condensation or shingle failure.  It appears that some type of house wrap was applied direclty over the SIPs and the shingles applied directly over that.  There was no venting space created- no ridge vent.  The house is a post and beam construction from WoodHouse- vaulted ceilings- no attic space.  I contacted Wood House- there only suggestion was to contact Murus.  I have contacted Murus but their repair suggestion has me a little skeptical.  Additionaly it appears that Homeowners insurance will not cover this.  The house was built in 1991 and I purchased it 2 1/2 years ago. Any thoughts and input would be greatly appreciated.  Thank you.

Your geographic location and a brief discription of your type of climate will help greatly in making suggestions. It matters.

The house is located in the Tidewater Area of Virginia- south eastern are. Mild climate- typical 4 seasons. It can get hot and humid during the summer, but the house is covered by shade the majority of the day.

If it looks like this, then it is a common problem with OSB SIPs:

Click here

The shade actually slows solar heating of the roof, which slows any drying potential that may exist.

Given the age and description this maybe stressed-skin panels rather than SIP construction, but they are related. If there are supporting rafter beams under the roof panel every 4' or so the repair options are simpler than if the panel itself is a more structural element, with the outer skin contributing to the structural rating.

Have pictures of both the exterior damage and the interior ceiling?

Pictures are kind of necessary because the pattern of water damage can clue you into the cause. For instance, if you have water damage directly below a roof vent then maybe the roofing isn't sealed or flashed properly around that vent and rain is getting in. However, if you have moisture damage all along the ridge of the roof or the damage follows the line of the panel joints, then you may have a condensation problem related to the panel connections having air voids in them where warm moist air is meeting cold air on or inside the panel.

So, what did Murus suggest as a repair solution?

It's very hard for anyone here to make any sugestions without seeing the extent of the damage.

I hope you can make out the damage with the attachments- they are pretty small- only allowed 100kb.  It is post and beam construction- I believe the beams/rafters are at least 4x8 and are on 4' centers.  I dont believe the sip's are considered part of the framing- WoodHouse gives a lifetime warranty on their framing, but take no resposibility for the SIPs.

Don't see any attachments/photos in your post.

Sorry about the attachments- thought I had added them.

I'm not too sure how to attach the files- I have 3- I see them and hit the green + sign- but they dont show up in the post.  please help!

roof_2_smaller.JPG

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rpeacock,

There's one more step after pressing the green upload button. Once your item is uploaded look down to where it is listed on the upload roster and select the 'insert' into post button.

Ok- it looks like I have it- please find the attachments- thanks for your patience.

Thanks for your input- I dont know if I am over killing by responding to 2 people but I am responding to one other post with the pics.  There exposed supporting rafters- 4x8 with tonge and groove wood panels on top- SIPs are over these.  Wood House does not consider the SIPs part of the structural element.

rpeacock; very disturbing the roof is a total loss, SIP is short for STRUCTURAL insulate panel. You need to go back to the insurance company again or get a lawywer

How widely spaces are the 4x8 support rafters? Is the t & g ceiling 2x6 goods?

If the spacing tight enough and with 2x ceiling it's there's some chance that this could be salvaged with anl over-skinning of the SIP through-screwed to the inner skin or rafters with timber-screws, and a vented nailer deck above that. But Chris may right- it could be totaled.

This sort of damage can be largely avoided in new construction with a furring-mounted ventilated nailer deck above the SIP skin. Vented nailer decks can't trap moisture against OSB under the finish roof- both the nailer deck and the SIP skin dry into the gap, and even leak damage ends up highly localized. On a roof with lines that clean & simple 2x4 furring with Cor-a-vent or similar at the soffit edge, and a standard ridge vent is adequate venting. On more complicated roof lines segmenting the furring into 18"-24" sections with 12" of space between segments to allow cross ventilation would be advisable.

Wow, that looks really bad. Something seriously went array here.

Are the walls OSB SIPs?

My gosh that's extensive damage. The damage pattern doen't look like a condensation problem to me 'at first glance'. I 'think' the underlayment and finished roof failed. Part of it 'looks like' the ridge shingles allowed water to get in and drip down the roof in places. Part of the eaves 'look like' water or ice got trapped at the bottom along the roof edge which could be 'ice damming'. I have two questions related to part of the damage.

1. Was the underlayment installed over the metal drip edge(correct) or was the drip edge installed on top of the underlayment?

2. Was the underlayment installed horizontally(correct) or vertically?

Just curious. Answers may determine the cause of the damage.

It's definitely not primarily a condensation/exfiltration problem, but there may have been a contribution in areas. It kooks more like an underlayment problem and/or leakage damage (maybe with ice-damming, if this is in a snow zone?)

With SIP roofs the shingles and underlayments can leak for years without dripping through to the interior. Using housewrap as an underlayment is a dubious choice at best, since the high vapor permeance guarantees a lot of moisture transfer from the shingles into the OSB when the sun hits rain or dew wetted shingles.

A vented nailer deck for the shingles may seem like an unnecessary extravagance at the outset, but it cures a lot of ills, making it a much more sustainable & durable structure, a structure that will tolerate failing shingles and some amount of deferred maintenance. Compared to the price of repair/replacement SIPs its downright cheap.

I'm with Simon it looks like leakage from top, too far up for ice damming