Is this an early sign of delamination?

rmartini · 02-19-2011, 08:46 AM

I am in the process of recovering from some pretty significant water damage in my house - the drywall was stained, the insulation was wet - so it all came down. I believe the issue was condensation from having non-ic rated recessed lights in cathedral ceilings. Also we did not have enough insulation (R-19 Batt), and there was no vapor barrier. We have clear soffits and a ridge vent, but the baffles are not continuous between the two - so that is not ideal either.

At this point we have the sheathing exposed and are trying to dry out the roof/trusses. The temp is about to drop again (michigan) so I need to get something figured out ASAP. I am concerned that the decking is going to delaminate so I am hesitant on just re-insulating and drywalling.

Here are some pictures. The first is immediately after we pulled down the insulation, then the second is after a few hours of drying, and the third is what it looks like now after nearly 3 days of drying.

(drying consists of several industrial fans directed at the roof and dehumidifiers, etc)

Is this plywood shot?

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**Scott Patterson** · 02-19-2011, 12:07 PM

Originally Posted by rmartini

I am in the process of recovering from some pretty significant water damage in my house - the drywall was stained, the insulation was wet - so it all came down. I believe the issue was condensation from having non-ic rated recessed lights in cathedral ceilings. Also we did not have enough insulation (R-19 Batt), and there was no vapor barrier. We have clear soffits and a ridge vent, but the baffles are not continuous between the two - so that is not ideal either.

At this point we have the sheathing exposed and are trying to dry out the roof/trusses. The temp is about to drop again (michigan) so I need to get something figured out ASAP. I am concerned that the decking is going to delaminate so I am hesitant on just re-insulating and drywalling.

Here are some pictures. The first is immediately after we pulled down the insulation, then the second is after a few hours of drying, and the third is what it looks like now after nearly 3 days of drying.

(drying consists of several industrial fans directed at the roof and dehumidifiers, etc)

Is this plywood shot?

Whenever you see plywood splitting as it is in your picture, it is in the delimitation process. It is becoming brittle and is basically at the end of its life. With the snow loads you can expect in your area you might end up like the roof in that Allstate insurance commercial and Mayhem!

rmartini · 02-19-2011, 12:13 PM

Originally Posted by Scott Patterson

Whenever you see plywood splitting as it is in your picture, it is in the delimitation process. It is becoming brittle and is basically at the end of its life. With the snow loads you can expect in your area you might end up like the roof in that Allstate insurance commercial and Mayhem!

Thanks for the reply - that is what I feared.

Allstate is my insurance company - but they have been reluctant to replace the roof.... sigh

**Eric Barker** · 02-19-2011, 06:07 PM

Since you have had condensation in each rafter bay, and I doubt that there was a ceiling can in each one, I'm going to lean towards ventilation problems. All that's needed is one spot where the insulation blocks air flow in the run between any two rafters.

You mentioned that the cans were not I.C. rated but you didn't say that they were air tight. Cans that are only I.C. rated are basically air vents for conditioned air to pass through into the roof structure.

As you have this corrected I suggest that you watch every step of the work. Many contractors, and certainly most laborers, don't fully appreciate the needed attention to detail with venting vaulted ceilings.

**Bob Knauff** · 02-19-2011, 08:08 PM

Unfortunately I have seen this problem in the past with vaulted ceilings and can light fixtures. It was so bad in one case that water actually dripped out of the fixture onto the floor on a regular basis during the colder winter months.

Even if the cans are IC rated, they still leak tons of air. They also generate heat to the housing that warms the cavity above and melts the snow on the roof causing icing. Can lights are simply a bad design for protruding into an attic or vaulted situation.

You may not like the suggestion but the true fix is simply to NOT have penetrations in the ceiling. Re-insulate the space, seal it up with drywall, and mount surface lighting. Anything less will most likely result in the same problems you are having now.

The plywood IS in the first stages of delaminating, as Scott pointed out. If it is not too bad it should be fine for distributed snow support but may be if'y for spot loads like walking on it.

**Markus Keller** · 02-19-2011, 09:54 PM

Two important issues here as far as structure.
The plywood is shot. This is clear from the amount of splitting as Scott mentioned. The plywood is essentially individual layers now.
The other important issue here is that you really need to remove the plywood in order to get the moisture out of the top of the rafters. Without removing the plywood, the moisture will stay trapped and rot out the top 1/2" to 1" of the rafters. Once this happens you can repair and renail the shingles all you want and it won't matter.
I am not speculating here, I've done this job numerous times over the years. I suggest you insist the insurance cover a complete tear off.
As far as cans, insulation and ventilation there are many options. Good and bad. Get the right info and install all components properly.

**Dom D'Agostino** · 02-20-2011, 06:28 AM

Originally Posted by Markus Keller

I suggest you insist the insurance cover a complete tear off.

Most insurance won't cover something like that. Typical coverage is to repair sudden losses, not issues that happen slowly over time, (Like the delaminating plywood.) They may pay for the interior damage and clean-up work, but the roof and sheathing is another story.

I've read about the record number of ice dam problems due to the odd weather patterns lately.

**Raymond Wand** · 02-20-2011, 08:53 AM

What thickness is the sheathing? 3/8 or 1/2 inch?

**H.G. Watson, Sr.** · 02-20-2011, 01:55 PM

Bracing should be in place to avoid warpage during the drying process and to maintain structural stability prior to removing sheathing.

I suggest you consult with a remedial architect or structural engineer to review and design a remediation plan, complete with specifications on how to brace and support during the dry-out/clean-up and remediation process.

Same can suggest and design (possibly minimal cost since interior stripped and decking will be replaced) alterations which may safely provide for more insulation and/or ventillation.

Several of the rafters to the right appear stained dark - the roof superstructure should be analyized on-site regarding integrity.

There is an area of the forum dedicated to "Questions from Homeowners, Homebuyers, and DIYers". You may find your topic has been relocated to that area of the forum sometime in the future.

**ROBERT YOUNG** · 02-21-2011, 03:57 AM

Originally Posted by Bob Knauff

Unfortunately I have seen this problem in the past with vaulted ceilings and can light fixtures. It was so bad in one case that water actually dripped out of the fixture onto the floor on a regular basis during the colder winter months.

Even if the cans are IC rated, they still leak tons of air. They also generate heat to the housing that warms the cavity above and melts the snow on the roof causing icing. Can lights are simply a bad design for protruding into an attic or vaulted situation.

You may not like the suggestion but the true fix is simply to NOT have penetrations in the ceiling. Re-insulate the space, seal it up with drywall, and mount surface lighting. Anything less will most likely result in the same problems you are having now.

The plywood IS in the first stages of delaminating, as Scott pointed out. If it is not too bad it should be fine for distributed snow support but may be if'y for spot loads like walking on it.

Can lights or pot-lights are problematic at the best of times for attic and roofs .
I explain to my clients. I own a façade restoration company and have worked inside and out for 35 plus years now, I take out the pot-light fixtures , insulate, install track lighting.
I some cases that is all you can do. Cathedral ceilings being a prime example.
If there is any space to vent, you apply sawfit venting and deck venting systems.

Joao Vieira · 02-21-2011, 06:49 PM

Lights in the ceiling are a pain in the but anyway because people often don't read the small print (me included

...) with proper ventilation, all should be good. I have canned recessed lights but never had a problem because we have 2 2' exhaust fans in our attic that are triggered with a thermostat at 100 degrees Fahrenheit.

It's not difficult to do...any electrical supply shop should have those. The wires in my attic don't have a metal jacket since the house is old but the DIYers need to get the wiring with the jacket to comply with today's code....but...what I am saying???/you are all inspectors...