Fixing Interlocking Concrete Tiles

[IgamOgam]

I'm considering having my roof replaced in advance of fitting Solar PV panels, and having new membrane, tiles, eaves ventilation, dry ventilated ridge, dry verge, fascias, soffits, guttering etc, and then fitting PIR board between and under the rafters to bring the insulation up to spec.

I have a 1971 Wimpey built 3 bedroom semi-detached with interlocking concrete double roman tiles. I understand that the extent of the repairs mean that building control approval is required, though some of the roofers I have approached either don't know this or don't seem to care.

The roofer I am dealing with at the moment has suggested that on the front elevation of my house (where my roof is on the right and my neighbours on the left with a chimney between us) he will not be able to double fix the tiles (BS 5534?) without installing a bonding gutter. I don't see why this is the case, but I assume it might be something to do with the tile interlock requiring them to be laid/fixed from right to left (ie toward my neighbours roof). Is this the case?

Also, my understanding is that a bonding gutter is intended for weathering the joint between two DIFFERENT roof coverings, but I would be replacing the existing double roman tiles like-for-like with double roman tiles, so I can't see why this would be necessary. Also, using bonding gutters requires disturbing my neighbours roof by crossing the party wall line between us, so I really, really don't want to do this.

Looking around my estate I cannot find a single instance where someone has replaced their roof and used a bonding gutter to do so.

Advice and opinions welcome

 

[diy_fun_uk]

I'm not a roofer, however what comes to mind is this. If you're saying there are other re-roofs on your estate that appear to be completed to a good standard and haven't used the bonding gutter, perhaps this indicates the contractor you're speaking with is concerned they don't have the skills to complete the job that way, so they're opting for the bonding gutter approach? Is there scope for you to seek quotes from a second and maybe third roofer? If they all say a bonding gutter is required (without any prompting from you one way or the other) this maybe indicates it is required for whatever reason?

Also make sure the 'roofers' you're speaking with are actually roofers with a proven track record.

 

[IgamOgam]

I'm not a roofer, however what comes to mind is this. If you're saying there are other re-roofs on your estate that appear to be completed to a good standard and haven't used the bonding gutter, perhaps this indicates the contractor you're speaking with is concerned they don't have the skills to complete the job that way, so they're opting for the bonding gutter approach? Is there scope for you to seek quotes from a second and maybe third roofer? If they all say a bonding gutter is required (without any prompting from you one way or the other) this maybe indicates it is required for whatever reason?

Also make sure the 'roofers' you're speaking with are actually roofers with a proven track record.

They are a Federation Of Master Builders member. I know that isn't a guarantee of good quality or knowledge in and of itself, but they were the first roofer I've spoken to that recognised that Building Control approval was a legal necessity, which at least gave me a small measure of confidence in them.

After a bit of initial confusion, my local Building Control has confirmed that because the tiles are the same both sides of the roof between myself and my neighbour (ie Double Roman) there is no requirement for bonding gutters to be fitted, which is not only what I would have expected, but also is a big relief in not having to disturb my neighbours roof tiles.

Building Control have raised a new issue however, as they say a firestop must be added if there is not one at present. As the house was built in 1971, I'm willing to bet there isn't one, so that's something I'm going to need to look into further and maybe add to the roofers quote.

So, my one outstanding question is whether it's easy, difficult or impossible to nail AND clip interlocking tiles that are laid right to left on a roof elevation where my neighbours roof is on the left hand side? I can think how I might do it, but I'm not up on a roof with a row of tiles in front of me!

 

[datarebal]

Retile with the same make and tile type (marley double roman, or Redland 50) will go back as they came off.
If it was a much earlier Marley version the channels were different .. but way beforev1971.

A picture zoomed into the tile will allow proper identification and ten potential issues if any ..

 

[IgamOgam]

Retile with the same make and tile type (marley double roman, or Redland 50) will go back as they came off.
If it was a much earlier Marley version the channels were different .. but way beforev1971.

A picture zoomed into the tile will allow proper identification and ten potential issues if any ..

I intend to. I took one of the existing tiles off the roof to try and identify whether it was Marley, Redland, or Sandtoft etc, but there are no manufacturer marks visible, so I'm still not certain, though at the moment my roofer has gone with Marley Double Roman Smooth Grey.

I've attached some photos of an existing roof tile alongside a Marley double roman. Maybe someone can definitevly identify them?

 

[datarebal]

The original is marley

 

[IgamOgam]

The original is marley

I'm not doubting you, but is this an educated guess or are you 100% certain?

 

[kp00110]

So, my one outstanding question is whether it's easy, difficult or impossible to nail AND clip interlocking tiles that are laid right to left on a roof elevation where my neighbours roof is on the left hand side? I can think how I might do it, but I'm not up on a roof with a row of tiles in front of me!

surely the tiles will have to be laid left to right starting where they meet the neighbours , so you have no issues where new and old meet

You suggest tile are laid right to left (probably suits how they interlock), so working in towards the joint between old and new rather than working out from it

Maybe this is why roofer is saying if you want to nail and clip you have to work right to left, can't work from left to right because you won't be able to lift and slip in the next tile etc, so to nail and clip will have to work from right to left and then bonding gutter is therefore needed as the joint spacing on the boundary won't work out?

Think it's a communication thing

Also why pir rafters why not just upgrade Loft roll would be much cheaper and easier I believe

 

[IgamOgam]

surely the tiles will have to be laid left to right starting where they meet the neighbours , so you have no issues where new and old meet

You suggest tile are laid right to left (probably suits how they interlock), so working in towards the joint between old and new rather than working out from it

Maybe this is why roofer is saying if you want to nail and clip you have to work right to left, can't work from left to right because you won't be able to lift and slip in the next tile etc, so to nail and clip will have to work from right to left and then bonding gutter is therefore needed as the joint spacing on the boundary won't work out?

Think it's a communication thing

Also why pir rafters why not just upgrade Loft roll would be much cheaper and easier I believe

My thinking was to loosely lay the first course of tiles, from left to right, lifting each one slightly to interlock the next, then adjusting the spacing so that the rightmost one ends up in the right place. Then work from right to left, lifting tile 2 to clip tile 1, then tile 3 to clip tile 2, etc. Then nail them all. This sets the position of the tiles in the next row, so lay them, then repeat the above exercise to first clip all the tiles, then nail them all.
There are roofs all over my estate that have been renewed so I can't believe this hasn't been done before
On the other point, my loft was boarded out with T&G decades ago which I'm not about to rip up. Putting the insulation between & below the rafters will also stabilise the temperature inside the loft.

 

[datarebal]

surely the tiles will have to be laid left to right

not so , if you do tile left to right you wont be able to clip them

Good practice is to line the roof out.