Low pitch tiled roof on extension

jabaroon

Hi All,

Hopefully someone with roofing experience might be able to put my mind at ease. On an extension that I have having built at the moment, the pitch is only about 10 degrees.

I know that this is no good for tiles, but wanted the tiled finish. As such, the builder has used torch on felt to completely water seal the roof. The nailed battons horizontally accross the roof on top of the torch on and laid the tiles on top.

I know that the tiles wont do their job 100% coz of the pitch, but now I am concerned that water that does get up under the tiles will actually be prevented from running off the roof by the horizontal battons onto which the tiles are laid?

Am I worrying needlessly?
Cheers,
Jab

Victor

Did he not raise the battens with counter-battens? (battens going perpendicular to the slating battens, i.e. down the slope)

jabaroon

Victor wrote:

Did he not raise the battens with counter-battens? (battens going perpendicular to the slating battens, i.e. down the slope)

Errr....Nope

It is looking distinctively like I need to have a little word with him???

Victor

Well, who ordered him to put slates on a flat roof?

jabaroon

Victor wrote:

Well, who ordered him to put slates on a flat roof?

Nope, I specified a requirement! His implementation of the requirement is flawed!!

CLADA

Yep! Know the problem, chanced my arm on a 12 degree pitch and my problem was the wind pushing the rain back up the tiles. In the end went and put the tile effect on from Nordmans. Have a look at www.nordman.ie

jabaroon

CLADA wrote:

Yep! Know the problem, chanced my arm on a 12 degree pitch and my problem was the wind pushing the rain back up the tiles. In the end went and put the tile effect on from Nordmans. Have a look at www.nordman.ie

Thanks for the info. All the materials have been bought and about 70% of the tiles laid on the roof before I spotted the potential problem today. What I am hearing is that water is definatley going to penetrate with a 10 degree pitch and therefore lodge at the horizontal battons. Its unlikely that a leak will occurr as roof is already watertight with torch-on felt, but the water lodging will definatley rot the wood,smell???.....gotta get this fixed me thinks.

Any suggestions?

Mellor

jabaroon wrote:

Thanks for the info. All the materials have been bought and about 70% of the tiles laid on the roof before I spotted the potential problem today. What I am hearing is that water is definatley going to penetrate with a 10 degree pitch and therefore lodge at the horizontal battons. Its unlikely that a leak will occurr as roof is already watertight with torch-on felt, but the water lodging will definatley rot the wood,smell???.....gotta get this fixed me thinks.

Any suggestions?

I wouldn't be so sure about the leak.
Are you sure the roof is stil watertight.
How are the batten fixed to the roof??

muffler

At some time in the future I can see a large piece of heavy duty PVC on top of the roof held down with a few concrete blocks

Victor

Oh, is the builder smarter than you think and included a cross slope?

rooferPete

Hi,

When a builder reads a specification he can advise you that it is not good practice or he can do what he is told, in this case it appears that he is doing what he is told.

FWIW I would have walked away.

Torch on is a generic term, my first question would be what is your roof covered with ?

Slate or tiles at 10 degrees will not work, that is why products like the Nordman, Kingspan (and others) developed tile sheets.

Even with a lath running vertically and cross battoned on the roof it will leak eventually possibly damaging your plywood deck.

You do have the options of zinc or copper standing seam roofs that can be fitted to a suitable underlay laid on the torch on felt.

.