New Slate Roof Problems Log Out | Topics | Search
Moderators | Register | Edit Profile

Slate Roof Central Message Board » Slate Roofs » New Slate Roof Problems « Previous Next »

Author Message
Top of pagePrevious messageNext messageBottom of page Link to this message

Kwigle
Posted on Tuesday, October 08, 2002 - 01:29 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

We have a huge mess. We live in coastal California, near Santa Barbara. Our 4-5 year old home has moisture and mold problems in the crawlspace, walls and attics. There is very high humidity in the house causing damage to floors, finishes, furnishings as well as negative health effects

We have tried to remedy problems from the ground up with some success however are now focusing on the slate roof as a possible contributor. We have a very complex Old-World style roof with lots of changes, dormers, deep eves and wood trim and rafters.

They used plywood sheeting, 2 layers of 40 lb. felt, 100 sqs. of Strata Grey China slate, copper flashing, nails and gutters. We used a red rounded clay tile ridge cap. 95% of the roof is over a concealed, insulated space with finished ceilings of tongue and groove or drywall and no venting, not even in the small attic spaces which are also insulated with fiberglass kraft covered batts.

It is beautiful however some slates are cracking in half and falling into the valleys or the ground. It is frequently damp and wet with condensation, some north side green moss growth, it looks uneven in places, there is water spotting on the underside of covered porches and the extensive wood trim and rafters are chalking and splitting with deterioration.

What can you recommend as far as the possibility of construction defect in design or installation? Should anyone involved have known to better ventilate a slate roof? What is standard practice?

Can we go back and ventilate with an attractive and functional ridge? Is that a band aide approach to a plywood vs. solid board sheeting issue?

The roof was guaranteed for 5 years. Would plywood delamination be considered failure?

Do you know of any inspector/installer in my area qualified to evaluate this problem?

Thanks for your advice and help.
Kwigle
Top of pagePrevious messageNext messageBottom of page Link to this message

kwigle
Posted on Thursday, October 10, 2002 - 11:39 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

P.S.

I just found out that the roofer "Hot Mopped" with heavy asphalt paper and tar on my porch roof which has multiple water stains on the wood T&G on the underside of the ceiling. Does that affect the longevity of the this particular roof and would that cause the water staining?

Thanks,
Kwigle
Top of pagePrevious messageNext messageBottom of page Link to this message

Tim Dittmar
Posted on Thursday, October 10, 2002 - 08:13 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Dear Kwigle/s- I've been working on a response for you but it's been difficult- much of what you've reported seems gapped(data-wise) and I've probably got as many or more questions for you as you have for whoever would help.... a real-time exchange would probably be the best to move forward efficiently with separating out the major causes of your myriad symptoms- does your insurance company have input in this yet? may be they should before "it" gets really bad- you know, like send over a moisture mitigation specialist? Were moisture barrier treatments omitted in the construction phase- do you have an especially wet lot with poor drainage treatments? The broken slates are probably just ones damaged by over-driving nails when they were installed- the exterior roof dampness is probably also normal- cold stone and warm, moist Pacific air condensing out as "dew"? The inadequate/non-existent ventilation of the roof won't be really altered by ridge venting and the expense/disruption is high/risky- consider some thermostat-controlled power venting? Like I said, have lots of questions to more fully understand before advising but whoever alters the roof shouldn't necessarily be your sole advisor on the subject- your problems evidently relate to many potential causes- e-mail me slateconsultant@aol.com
Top of pagePrevious messageNext messageBottom of page Link to this message

SlateGuy@neslate.com
Posted on Friday, October 11, 2002 - 02:41 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Kwigle,
Independent of the lack of ventilation I would be very concerned about the slate.

It may well be, as Tim said, that some slate was damaged by overdriving the nails, but if this is the case, it is not a trivial matter. It indicates inexperience and/or bad workmanship that may plague the entire roof for the rest of its useful life. Slate doesn't fail due to moisture unless it is exceedingly soft and absorbing rather than shedding moisture. Moss growth on the slate indicates to me that the slate is retaining moisture. The slate might be failing regardless of how well or poorly it was installed.

Quality issures with some Chinese slate are well documented (you will find them on this Web Site). There are far too many cases of catastrophic failures from certain Chinese slate within a few years of installation. How old is this roof? If it is still under warranty, you should explore your options. Despite great strides in quality in recent years by some Chinese producers and importers, there is still lots of junk available.

The siren song of "cheap, cheap, cheap... slate is slate... it all lasts forever... buy the cheapest" is very tempting and misguided.

Are you replacing the breaking slates? If not, then you undoubtedly have leaks unless the two layers of 40# felt and the "hot mop" are keeping the water infiltration at bay. Why did these guys go to such lengths to waterproof under the slate? Perhaps they were nervous about the material???

You need an unbiased evaluation from a slate roofing expert. Not me, but there are others on this board who can provide. Heck, talk to Joe. After all, he "wrote the book."

Best of Luck,
SlateGuy
Top of pagePrevious messageNext messageBottom of page Link to this message

Larry OBrien
Posted on Saturday, October 12, 2002 - 10:33 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Maybe its the pitch of the roof and the exposer of the slate. I agree with slate guy when he said why did these "ROOFERS" go to the trouble to hot mop. Tells my they where trying to cover all bases

COPPERMANANDSON@AOL.COM
Top of pagePrevious messageNext messageBottom of page Link to this message

kathleen wigle
Posted on Thursday, October 31, 2002 - 05:45 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

New information from original poster.

Today my roofer opened up our roof in a couple of spots and does not like the look of the two layers of 40lb felt as it has melted together and is bubbled due to extreme heat. He says it looks as if was "hot mopped". He said it has deteriorated prematurely and may crack and leak due to the brittleness. The slate was hot as was the plywood. The framing nails are significantly rusted and the underside of the plywood has black condensation marks on it . In another place the felt was OK however the plywood was covered with mold growth. he is still recommending ridge vents.

In addition to my other descriptions he had applied Bithethane to the peak of the roof under the red tile cap. He was concerned about the ridge tile leaking so added it when he installed it almost 5 years ago.

There is no insurance coverage for construction problems in absence of an actual leak incident. We built this house 96-98 and it had 16 inches of rain on the framing before close in. After close in we had 46 inches of rain during el nino. The ground was saturated and combined with bad grading on a slope location, no foundation drainage or waterproofing and a crawl space below exterior grade we were wet but no one knew. There was no screed installed on the plaster exterior which was also continued below grade and wicked up water and saturated the mud sill and framing and got further trapped by the bithathane strip applied over the mudsill and foundation connection. There were some leaking porch posts and some water running down the walls and into the foundation vents when it rained. However any moisture got trapped due to the 5,000 sq ft crawl divided up into "rooms" with a continuous stepped footing with plywood shear panels which prevented airflow. The trapped moisture plus high coastal humidity and an over pressured crawl due to prevailing ocean wind on exposed site caused the humidity to be as high as 95% in the crawl which saturated (16-23% moisture) the Trus joist I beam joists and microlams. We have opened it up and installed an Atmox fan system and covered the dirt floor with plastic as well as pulled the exterior clay soil away from around the foundation however it is still 76% humidity with the joists as high as 18-20% and we haven't had much rain in 18 months.

With a 3 and partly 4 story house we have tremendous stack effect and there was no way for the moisture to escape except into the house, walls and ceilings. 90% of our roof area is over vaulted T&G and beamed or drywalled ceilings with a concealed 2x12 rafter space which is heavily insulated under the plywood, then 2 layers of 40 lb felt and the slate. We do have some attic space on the 3 levels. Nothing was vented and we have heaters located in the attics and crawlspace without make up air and well as leaky ducts. The penetrations in the subfloors were not sealed properly and the insulation was incorrectly installed in some areas. We also have thermal bridging due to metal I-beams which caused condensation and wood decay. While trying to convince my husband, architect and builder there was a problem I have tried to discover the sources of the moisture leading to mold growth and high interior humidity. Which has now caused us to suspect the roof and the lack of ventilation as a contributing factor.

We have a 3 million dollar house built by the best architect and builder in town(???) that is molding and decaying and making us sick. We can not afford inexpensive fixes. We may have to sue after all is said and done because the original building team certainly can not afford to fix all the problems and their insurance will only kick in after credible legal action. We have a construction defect team working with us since July which had not considered the roof until my roofer suggested we might have a problem when he came out to fix the destructive testing done to check the flashing and details at a porch/wall/roof connection.

So back to your expertise. Do you think Ridge vents would help? What about venting for some of our shed type roof/wall intersections and all the valley's and dormers? We are in a high fire area and may be prohibited from having eave vents and even if we could would still have some problems with the insulation and blocking inhibiting air flow. What type of ridge vent do you recommend and how can we go back and retrofit the roof. If the paper fails due to heat and melting will the roof fail? Are 2 layers of 40 lb. felt causing additional problems? I thought we bought and paid for a 100 year roof. Should my roofer's warrantty cover any or all of the roof repairs. Who should have known to install ventilation? What is considered standard industry practice? Is there a southern California slate roof expert who can evaluate this problem, offer remedies and specifications and provide reports to the Construction defect team?
Top of pagePrevious messageNext messageBottom of page Link to this message

admin
Posted on Thursday, October 31, 2002 - 11:12 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Standard slate roof installation practice has always been slate installed over boards (not plywood) with one layer of 30 lb. felt on a roof slope exceeding 4:12 in pitch, preferable 8:12 or greater. This standard has been tried and proven many, many times over centuries and does guarantee a 100 year (if not longer) roof. The switch to plywood roof decks under slate has begun in earnest in the United States (only), and brought with it problems of ventilation, etc. There is a strong effort in the US right now to make a plywood roof deck the standard for the slate industry, which is a huge mistake.

In any case, given your situation, you may want to try installing a ridge vent system. The people to contact are Castle Metal Products at 847-806-4540.
Top of pagePrevious messageNext messageBottom of page Link to this message

SlateGuy@neslate.com
Posted on Monday, November 04, 2002 - 04:15 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Wow! 46 inches of rain is some serious moisture (and I lived in the pacific northwest in another life).

I'm not sure where you are located, but Michael Gibbons has done some beautiful roofing and slate work up and down the California Coast. He knows his stuff:

Michael J. Gibbons Slate Roofing Co.
3344 Market Street
San Francisco, CA 94114
415-864-6862

Best of luck,
SlateGuy
Top of pagePrevious messageNext messageBottom of page Link to this message

SlateGuy
Posted on Monday, November 04, 2002 - 04:17 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Duh, I re-read the posts. You're near Santa Barbara. I'm not sure if I have any recommendations for that area.

SlateGuy
Top of pagePrevious messageNext messageBottom of page Link to this message

Ray
Posted on Wednesday, March 17, 2004 - 01:34 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Hello,

Also regarding mold expert in your arear you can find more info at http://www.moldage.com
Top of pagePrevious messageNext messageBottom of page Link to this message

Stankodej
Posted on Wednesday, April 07, 2004 - 03:07 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Water loss and MOLD test & remediation services, free info .
CALL 1-800-201-8103 or visit http:/www.aquarestoration.com
Top of pagePrevious messageNext messageBottom of page Link to this message

Dean S.
Posted on Monday, May 17, 2004 - 03:30 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Licensed And Certified Water Loss and
Toxic Mold Remediation Firm
Aqua Restoration is an emergency water damage restoration and toxic mold remediation company. Specializing in water removal, structure drying, contents and document restoration, sandbagging services, laboratory testing, microbial remediation (cleanup of toxic mold growth and microorganisms associated with a water loss or sewer back-up).

1-800-201-8103
We are California Based Mold Remediation Experts
For More Information Please Visit www.aquarestoration.com
Top of pagePrevious messageNext messageBottom of page Link to this message

Christine
Posted on Friday, May 28, 2004 - 03:50 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

How to test toxic mold in your home? How to remove black toxic mold?
Do you know about mold allergy? Our pat animals,
dogs, cats, horses... are also under influence of toxic mold. Where to find testing labs and mold inspectors? All about filters, cleaners, purifiers...
Call 1-800-201-8103 or visit www.aquarestoration.com to find out answers about mold!
Top of pagePrevious messageNext messageBottom of page Link to this message

Ray
Posted on Monday, June 21, 2004 - 08:35 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

MOLD INSPECTOR LOS ANGELES

MOLD INSPECTOR CALIFORNIA

CERTIFIED MOLD INSPECTOR

CERTIFIED MOLD REMEDIATION LOS ANGELES

ARE YOU AT MOLD RISK , CALL US NOW AT 1-818-624-6732 OR VISIT www.moldage.com

FOR MOLD INSPECTOR TEST AND REMEDIATION IN WOODLAND HILLS , BURBANK BEVERLY HILLS , LA CANADA , PASADENA , GLENDALE -CALL US NOW
Top of pagePrevious messageNext messageBottom of page Link to this message

Anonymous
Posted on Friday, October 01, 2004 - 05:40 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

I had black toxic mold in my house and was looking around the web to solve my problem. I knew that mold can destroy man's health and I was looking around and found lot of usefull informations and services on www.moldage.com , so I can recommend that website to the others with the water damage or toxic mold problem in their bildings or houses...
Top of pagePrevious messageNext messageBottom of page Link to this message

Ted Wetzel
Posted on Monday, October 04, 2004 - 09:43 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

As you may have guessed by the response here, mold is to be taken VERY seriously. Sometimes mold remediation takes an extreme approach. You are obiously putting a great deal of time into finding the best people to repair your home. I would also suggest that you are ready to sue earlier rather than later.

It seems to me that with 2 x 12 rafters there was plenty of space to provide decent levels of insulation AND adequate ventilation.

If the plywood deck is showing significant signs of failure now what do you think it will look like in 40 years? If I were the home owner there isn't any question that I would consider that a rather serious longterm concern.

I have read a few publications on the benefits of NOT venting a roof and the methods required to make it work. You may want to find someone qulified on how to implement that as an option.

This is purely opinion from a home owner. However I've worked in the construction industry all of my adult life and I've been in lots of these uber expensive homes. In that time I've learned that there are some good contractors out there that are promoted beyond their capability when someone asks them to build these monster homes.
Top of pagePrevious messageNext messageBottom of page Link to this message

Ted Wetzel
Posted on Monday, October 04, 2004 - 11:09 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

sorry, I keep getting caught out by how old most of these posts are. The other forums I frequent can have a few thousand posts a day so this response is next to usesless. Anybody know how this original poster made out?
Top of pagePrevious messageNext messageBottom of page Link to this message

Pamela S.
Posted on Wednesday, October 12, 2005 - 07:52 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

I just bought a 71-year old house in Washington, DC. The previous owner had the original Pennsylvania slate roof sprayed with some kind of aluminum paint. The inspector I hired found no signs of leakage, but said it was time for a new roof. I found a slate roof specialist and when he took the front slates off, sure enough, they were soaked through. They flaked and crumbled in my hand. I'm replacing the roof with Riverstone slate from Argentina, but it began to rain just as they finished laying the 30lb (UL) felt. The main roofer can't be here today, but his crew is and they're going ahead. Should they wait until the felt is dry or is the slate okay to nail in and it's they're safety I should worry about? This is expensive and important. I want it done right the first time.
Top of pagePrevious messageNext messageBottom of page Link to this message

Anonymous
Posted on Wednesday, October 12, 2005 - 03:46 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

You're alright, if they have the head lap fiqured corrrectly for the pitch of the roof you don't really even need felt, at all. The only true purpose felt really serves on a SLATE roof is to keep the interior dry during the slate installation process. As far as their safety well that's another matter hopefully the foreman/owner took all the proper safety pre-cautions and set the job up safely. Hopefully you where smart enough to get a copy (with you shown on it, you're name that is) of their worker's compensation insurance and their liability insurance. Otherwise from what I know you are assuming some (if not all) of the liability. This area of concern should NEVER be looked over by a homeowner, church board or any other type of committee or they could be asking for some trouble should anything go wrong (hopefully nothing ever does, go wrong) Good luck with you're project hopefully I answered your questions. But, however I do have one for you, why? did you choose a foreign slate over an American produced slate? Just a question.
Top of pagePrevious messageNext messageBottom of page Link to this message

admin
Posted on Wednesday, October 12, 2005 - 04:33 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Pam,

Have you read the Top 10 Mistakes Made
When Installing New Slate Roofs? If not, here it is:

http://www.traditionalroofing.com/TR4_mistakes.html

Also, did you look at the sample SLATE ROOF INSTALLATION Proposal we have on this site? It is here: http://www.slateroofcentral.com/install_contract.htm

The water on the felt will not hurt the roof. It will quickly dry out. Yes, it's dangerous to work on slate roofs when wet.

More importantly, you should have an adequate contract document which clearly states the specifications on the job (headlap, nail type, etc., etc.).

You should have done research before signing any papers. If you type "slate roofs" on Google and hit "I'm feeling lucky," you will go to my web site. It's that easy to access information about slate roofs these days, so no one really has an excuse to plead ignorance if they have problems with their slate roof installation. I'm not suggesting that you did not research the issue or that you will have any problems. Hopefully it will turn out to be a beautiful roof.

Take care,

Joe Jenkins
Top of pagePrevious messageNext messageBottom of page Link to this message

Pamela S.
Posted on Wednesday, October 12, 2005 - 11:25 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Dear Joe - My contractor is James Vosburg from PA. Perhaps you know him? Anyway, we do have a contract, tho' not as detailed as your excellent sample. The front is 1/4 done. I was concerned that rain would be a problem soaking through the felt, but your post and advice from the Roof Center in Bethesda eased my mind.

I understand that the Riverstone is a relatively recent import in the U.S. I like the look of it and hope it will be as durable as Vermont Green, which he said was comparable (the installed price is the same).

Thanks for checking this post. I didn't realize the other posts were so old at 7AM.
Top of pagePrevious messageNext messageBottom of page Link to this message

Pamela S.
Posted on Tuesday, October 18, 2005 - 09:57 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Dear Joe - I chose the Riverstone because I liked its look. Buckingham was too somber and the Pennsylvaia was so common. I didn't like the green. I found out later that Riverstone comes from Argentina, outweighs the Pennsylvania it's replacing and isn't that common here yet. It was only at that point that I thought that perhaps it would have been better to stick to the tried and true, American slate for our weather conditions, but the roofer already had it ordered. It looks beautiful now that the snow guards are up and I hope it lasts. The roofers plan to finish by Friday.
Top of pagePrevious messageNext messageBottom of page Link to this message

plavamala
Posted on Saturday, June 03, 2006 - 04:08 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Dear Joe, I was traveling throughout the web world and I have found this board. In addition to the information to this problem I would advise for everyone to check this link for additiona free information http://www.bibac.com/plavamala/

Here is more information about los angeles mold inspection information about toxic black moldremoval.com

Add Your Message Here
Post:
Username: Posting Information:
This is a private posting area. Only registered users and moderators may post messages here.
Password:
Options: Enable HTML code in message
Automatically activate URLs in message
Action:

Topics | Last Day | Last Week | Tree View | Search | User List | Help/Instructions | Program Credits Administration