Dry Verge fitment on a new slate roof

[frslam]

Hi all, Seasons Greetings. 

I have a question regarding Dry Verge (Scott Verge) on a slated roof. I received a rip snorter  kick back injury so couldn't slate the roof myself, my fingers are still there but the nerve pain is ridiculous in the cold.

Anyway, I employed a roofer to install membrane, Dry Verge and slate. The roof is 13400 wide x 5400 high (@ 250 wide slates, 53.6 slates - the roofer obviously didn't want to trim any and laid out 54 slates, 53 slates with a tiny gap between them would have been just about perfect imho). The slates are CUPA Heavy 3's @ 400x250. When the roofer installed the membrane and Dry Verge, he obviously just laid out the slates until they at least covered the roof and wherever the last slate landed, installed the Dry Verge. The slates were butted up tight to each other (I know in some places there should be a 2 - 3mm gap, not usual up here in the Highlands). I told the roofer that the gap between the Fascia and the inner edge of the Dry Verge was far too big, approximately 50mm too much at each end. I have another house opposite which has the same Dry Verge on a slated roof but fitted tightly to the Barge. The Dry Verge should run into the rain gutter, one of my concerns is that the way the roofer installed the Dry Verge, the rain gutter would protrude the gables excessively. 

There isn't a great deal of detail online regarding the placement of Dry Verge when installed with a slate roof. Personally, if it was me who was installing it, each end slate would have been trimmed by a couple of inches, or use 1 less slate per course and leave a small gap between each slate. The slater was wanting £11k for a couple of weeks (labour only), maybe it's my fault for expecting a more detailed finish. The membrane fitment in regards to the Dry Verge was terrible as well. The membrane should just 'lap' into the channel of the Dry Verge, but in fact it barely reached it. I mentioned to the roofer that I could actually see roof timbers between the membrane and the Dry verge. This caused the roofer to quit. 

In relation to the location of the Dry Verge (overhang), when I mentioned it to the roofer, he pointed out a line on the Verge, telling me he installed it correctly, according to that line. I thought he was just making excuses because the line he pointed to was a moulding which diverts any rainwater that gets through between any slates, into the Dry verge channel - similar to how lead can have a slight fold to divert water. He also told me that up here, we don't install membrane into the Channel because it 'wickes' water. I disagreed, membrane is designed to not wick water. The amount of slating that was done before the roofer quit was certainly nothing worth writing home about and to be honest, as peeved as I am that the roof isn't anywhere near finished, I feel that I've dodged a bullet, now that he's quit.

 

Does anyone have the definitive answer, should the Dry Verge be fitted as near as possible to the Fascia, regardless of how many slates are used in a course? Should the slates have been trimmed by a couple of inches at each end or use 1 slate less per course and add a tiny gap between each slate? I live in the North West Highlands and exposure to sometimes severe weather extremes can add another dimension to overhangs that are excessive. The old roof was lightweight fibre cement slates and they had a slightly less overhang, although there was no dry verge fitted back then, the tiles would still sometimes get ripped off in a storm. Am I being too fussy or expecting too much? Any advice would be so appreciated. Thanks  

[Mr Punter]

Hello @frslam.  This seems to cover most of the ground already explored in your thread earlier this week.

 

A small gap between slates is good as it reduces capillary action letting in water.

 

I understand that you considered that your roofer has not done the roof to your satisfaction and you have parted company, finishing the roof yourself or by others and you are now looking at who may owe money to whom?

 

I am not sure how this new topic will progress things.

 

 

[frslam]

3 hours ago, Mr Punter said:

Hello @frslam.  This seems to cover most of the ground already explored in your thread earlier this week.

 

A small gap between slates is good as it reduces capillary action letting in water.

 

I understand that you considered that your roofer has not done the roof to your satisfaction and you have parted company, finishing the roof yourself or by others and you are now looking at who may owe money to whom?

 

I am not sure how this new topic will progress things.

 

 

Hi Mr Punter, thank you for your reply. I did mention that there wasn't a great deal of information online regarding dry verge installation. I was hoping to get a perspective from a professional or experienced DIYer regarding how much dry verge overlap would be advisable, particularly in sometimes extremely wet and windy conditions, besides the obvious, that it just looks wrong to me. Hoping for an experienced person to say whether the preference would be a small gap between slates or trimming a slice of both end slates (or both) so the dry verge would butt right up to the barge board. Thank you.