Ventilation of Slate roofs Log Out | Topics | Search
Moderators | Register | Edit Profile

Slate Roof Central Message Board » Slate Roofs » Ventilation of Slate roofs « Previous Next »

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

Bud (Bud)
Senior Member
Username: Bud

Post Number: 56
Registered: 02-2010
Posted on Friday, February 18, 2011 - 04:38 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

A similar discussion was had here before and I will offer the same for this.

AirVent, Inc. makes a ridge vent that is copper, it comes in 10 foot lengths and has the external baffle that is so very important in a ridge ventilation product (it provides for the outward only flow of air and therefore prevents the intrusion of snow, dirt and moisture).

Slotted holes are standard in the product so attach it there as recommended by Old School. One key point when using this type of product, put a continuous bead of sealant under the flange roughly in line with the fasteners. This will provide a seal between the roofing material and the vent which is important due to the high pressure that will occur at the flange. Additionally the sealant will 'glue' the vent down tight for longer service. (please note, most of the repairs of this type product that I make are a result of too little fasteners and no sealant).

As for the net free air space, it will meet or exceed the soffit. This product provides 9 sq inches per foot per side which is the magic number in attic ventilation.

Hope this helps.
Top of pagePrevious messageNext messageBottom of page Link to this message

Old_school (Old_school)
Senior Member
Username: Old_school

Post Number: 590
Registered: 01-2009
Posted on Friday, February 18, 2011 - 08:22 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Pete, No I haven't, and not too many people use a vented ridge on slate. It is difficult to do, expecially when you are trying to use a slate ridge.

Perhaps the best way to do it would be to use the coravent and then install a "rolled copper ridge" over the top of it, instead of trying to fasten the slates over the peak. If you do that, you may have to install a copper wind baffle an inch or so beneath the bottom of the coravent with some weep holes every 6 inches to let out the water. That would make three pieces for every foot of ridge when it was done. You would also want to use brass screws to hold it all down with slots to allow for expansion, and some washers to spread out the pressure. A lot of work for sure.
Top of pagePrevious messageNext messageBottom of page Link to this message

Pj42 (Pj42)
New member
Username: Pj42

Post Number: 4
Registered: 02-2011
Posted on Thursday, February 17, 2011 - 11:40 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Thanks Old School, that is reassuring.

My roofer plans to install coravent at the soffit and the ridge. I'm not sure how he will attach the slate to it at the ridge.

The ventilation slots will be equal at soffit and ridge.

Have you seen previous use of Coravent with slate?

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

Old_school (Old_school)
Senior Member
Username: Old_school

Post Number: 589
Registered: 01-2009
Posted on Thursday, February 17, 2011 - 09:20 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Pete, I would imagine if you have a fully vented soffit and you have a fully vented ridge it should be fine. The air will always be moving that way. What do you plan on using for the ridge vent with the slate? Copper?

It is important that if you do this, that you make sure and balance the ventilation with the soffit and the ridge. Basically you will have a bunch of 2 inch "attics"
Top of pagePrevious messageNext messageBottom of page Link to this message

Pj42 (Pj42)
New member
Username: Pj42

Post Number: 3
Registered: 02-2011
Posted on Thursday, February 17, 2011 - 06:19 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Hello, The vent chute is what I call the 2" air space that ventilates from the eve to the ridge in the ridge vent system. A reflective layer on the bottom of that space would reduce the effect of radiant energy in the house below, but I don't want to do something that would be bad for the slate. Thanks for any help, Pete Johnson
Top of pagePrevious messageNext messageBottom of page Link to this message

Chris (Chris)
Senior Member
Username: Chris

Post Number: 83
Registered: 09-2009
Posted on Thursday, February 17, 2011 - 04:03 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

what is a vent chute?
Top of pagePrevious messageNext messageBottom of page Link to this message

Pj42 (Pj42)
New member
Username: Pj42

Post Number: 2
Registered: 02-2011
Posted on Wednesday, February 16, 2011 - 07:18 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Any opinions out there on the use of reflective materials below a slate roof?

I am installing vent chutes above a conditioned space attic for ridge vents.

I would like to know if it is advisable, inadvisable or inconsequential for the slate if I use a reflective surface facing up in the bottom of these chutes.

Many thanks,
Pete Johnson
Top of pagePrevious messageNext messageBottom of page Link to this message

Paul Mitsis
Posted on Monday, March 25, 2002 - 07:36 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

I have a question about the proper ventilation of an attic with a slate roof. I know slate breathes much more than most roofs. This is especially true with my current roof which has no felt and the occasional ray of sunshine peering through. All of the bids I have for the new roof involve laying down 30 lb felt (ok by me). However a couple contractors want to lay two layers of this over the whole roof and 90 lb in the valleys. Will this adversely effect the ventilation? The attic is poorly insulated (on the list of fix-ups) and has no real vents (ridge or gable-end) to speak of.
Thanks for the help.
Top of pagePrevious messageNext messageBottom of page Link to this message

Joe Jenkins
Posted on Monday, March 25, 2002 - 10:45 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

A single layer of 30 lb felt is sufficient under slate for temporary waterproofing until the slate is installed. Anything additional serves no real purpose. 90 lb in the valleys suggests the roofers have no confidence in their work and expect the valleys to leak. That's a red flag.

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