calling any roofers/ builders

[nev]

hi gents
Could someone please tell me or preferably point me to a pic or two of the correct practice for fixing flashing over concrete? tiles?
We have a stone built property with a single storey kitchen extension with a tiled apex roof (similar to marley eternit tiles).
the flashing is cut into the render on the house wall as i believe it should be and then projects out on the tiles for approx 3-4 in and hammered to fit the profiles of the concrete tiles, but sits on the top of all the tiles.
i have moisture running down the wall in the kitchen and after inspecting earlier i see that the tiles beneath the flashing are wet.
I believe that the water is not coming down the wall from above the flashing but making its way down the roof and under the zinc? flashing that sits on the tiles. (all the tiles are wet and the wall inside the flashing is not)
It is a particularly exposed area and gets some serious wind and rain blown at it!

should there be some kind of sealer/ bitumen type product sealing the length of the roof? or should it be an under / over type of fitting? (guessing)

Going to the builders merchants on Monday and it'd be handy to know if im looking for anything in particular.
thanks in advance
nev

 

[Dusty]

Evening Nev
You should have what is called a "soaker" under each tile , which is a piece of code 3 lead bent 90 degrees so you have approx 6" each side of the fold and it should be the length of the tile . each one is fitted under a tile with an upstand against the wall . the bottom of each will overlap on to the tile below it . this is a sort of secondary barrier . the idea being should a tile break then the rain will discharge on to the tile below .

The main lead flashing should be cut in as you say to the wall , on a solid wall ( no cavity ) you should aim for 50mm approx in the stone / masonary . this should be sealed with a lead silicone /mastik in the groove . you can then face it with mortar if needed for asthetics . from the top of the tiles you should have at least 100mm if you can of upstand as they say there is a minimum as the rain will "splash" back up . The lead should be no more than 1500mm in length due to expansion and must be overlapped atleast 100mm for each piece
Also the lead flashing should atleast reach in to one complete "valley" of a tile , if the tiles have been cut then work in the next one . The lead tends to be 300 plus wide and would be code 4

Another thing to look at is the felt , it should upstand a good 75 to 100mm up the wall with the lead covering it . once again the felt is not there to be relied on , another 2nd barrier .

If the felt is wet all along the wall it is as you say coming from further up .perhaps the ridge or the saddle flashing has failed . If the lead is not cut in deep enough then it may be working around that , and if not sealed with a sealant then it may be working around the pointing .

Would upload a piccy for you but i cant work out how to and all my images are too big .

Hope this helps but if you get stuck send me a pm .

Kind regards Sam

 

[nev]

Thanks Dusty, pm sent

 

[Jacob]

Neat picture here,

The soaker catches any water blown sideways towards the wall and takes it to the tile below.
The stepped flashing takes water draining down the wall on to the soaker.
Length is gauge+lap+1" which is equal to the covered length of the tile plus 1" to turn over the edge.

 

[nev]

cheers Jacob
looks like the guy that put my roof on had an aversion to soakers and felt- nothing there!

 

[Lons]

Hi Nev

The advice given is spot on htough putting in soakers afterwards is no small task so make sure you're up to it.

i suggest you download the Calder leadwork guide which is pretty much a trade "bible". A pdf file which you'd tell you all you need to know.
http://www.calderlead.co.uk/wp-content/ ... adwork.pdf

cheers

Bob

 

[dj.]

the flashing is cut into the render on the house wall as i believe it should be and then projects out on the tiles for approx 3-4 in and hammered to fit the profiles of the concrete tiles, but sits on the top of all the tiles.

That`s OK with your type of tile,you don`t need soakers but the over cloak on the tile should be at least 175mm, page 14 in Lons link shows what you need to do.


Regards.

dj.

 

[Dusty]

Cheers for doing that Jacob , cant sus out the hole resizing thing and links etc

Down yer we have to fit soakers as a matter of course for the B/I . It never hurts to as it is is more belt and braces , and the only thing I would do different is as the soaker shows but run it up to the next batton so exactly mirror the tile , if you cut the soaker about 25mm shorter than the tile and then by the time you fold it over the batten by about 15mm it will never show from below . If you have the opportunity I would also bend the far side of the soaker up so it acts like a trough and directs the water down only .

If you can by any means extend the felt up the wall , which will mean lifting the tiles to the next rafter and denailing them ( which is easy enough ) and lay a piece of felt all the way up and turn up the wall by 100mm or so then if the tiles etc fail then the felt will barrier any water .

I know we all have different ways but our B/I 's are "demanding " but it works

Kind regards Sam

 

[Jacob]

Cheers for doing that Jacob , cant sus out the hole resizing thing and links etc ......

I just lifted that one from the net so it looks like this in the text;

[img]http://www.leadsheetassociation.org.uk/assets/images/pocketguide/sosf.jpg[/img]

 

[nev]

thanks guys, much appreciated. looks like i will be adding roof repairer to my cv next week, weather permitting.

 

[Lons]

Soakers are part of building regs in all areas of England as far as I am aware, to prevent exactly the type of water ingress you've described. The Calder guide is part of the local authority library, I have one and it was used as a teaching aid in the construction dept of the local college. All the roofers and builders that I know have read it at some stage.

It's very clearly illustrated, easy to understand and free to download from the link I gave above. Building is my business and I strongly recommend you to take a look at it.

Cheers

Bob

 

[nev]

Soakers are part of building regs in all areas of England as far as I am aware, to prevent exactly the type of water ingress you've described. The Calder guide is part of the local authority library, I have one and it was used as a teaching aid in the construction dept of the local college. All the roofers and builders that I know have read it at some stage.

It's very clearly illustrated, easy to understand and free to download from the link I gave above. Building is my business and I strongly recommend you to take a look at it.

Cheers

Bob

already saved , to be digested with breakfast in the morning

 

[Lons]

already saved , to be digested with breakfast in the morning

Needent be a long breakfast Nev :lol: :lol:

 

[dj.]

Soakers are part of building regs in all areas of England as far as I am aware, to prevent exactly the type of water ingress you've described. The Calder guide is part of the local authority library,

Taken from page 15 of the Calder guide you linked to

"Soakers and step flashings are used to weather a raking abutment where
the roof is covered with slates or plain tiles. While Code 3 is suitable
for soakers, Code 4 is the minimum thickness to use for all flashings."

The tile Nev linked to are interlocking shaped concrete tile, not plain.
The installation of soakers on interlocking shaped tiles can have a detrimental effect on the performance of the roof.


Regards.


dj.

 

[nev]

Soakers are part of building regs in all areas of England as far as I am aware, to prevent exactly the type of water ingress you've described. The Calder guide is part of the local authority library,

Taken from page 15 of the Calder guide you linked to

"Soakers and step flashings are used to weather a raking abutment where
the roof is covered with slates or plain tiles. While Code 3 is suitable
for soakers, Code 4 is the minimum thickness to use for all flashings."

The tile Nev linked to are interlocking shaped concrete tile, not plain.
The installation of soakers on interlocking shaped tiles can have a detrimental effect on the performance of the roof.


Regards.

dj.

The clot thickens! they are indeed interlocking profiled tiles, and on further investigation this morning i found this ..
http://www.google.co.uk/url?sa=t&rct=j& ... 2k&cad=rja
which does state that soakers should not be used with such tiles.
it looks like i require either wider flashing to project further over the profile, clips to hold the edge of the flashing down or a secret gutter.
back up on the roof later today or tomorrow to have a good measure and inspection and pull a tile or two off to see what my options are. i will take my camera if i remember and update you later.
thanks again all
nev

 

[dj.]

Nev, secret gutters are only necessary with flat tiles, as long as you take the lead overlap well onto the tiles you shouldn`t have a problem.

Are you in an exposed location? what is the pitch of the roof?




Regards.


dj.

 

[nev]

Nev, secret gutters are only necessary on flat tiles, as long as you take the lead overlap well onto the tiles you shouldn`t have a problem.

Are you in an exposed location? what is the pitch of the roof?
Regards.

dj.

exposed location - yes, effectively the top of a small mountain adjacent to park/ playing fields, gets some serious buffeting.
pitch - a guesstimate, somewhere between 30 -45 degrees?

 

[Lons]

Hi Nev
I hadn't realised they were profiled tiles - didn't check the link #-o

The underfelt in this case should normally be lapped up a little on to the wall to stop and divert any water which blows under running down the wall behind the flashing.
The flashing on profiled tiles would be wide enough to lap over the first highest profile of the tile.

That's the way we do it anyway

Bob