upcoming extension advice

[mattu27]

Work had progressed from the last post of dodgy brickwork. We're now tiling the roof after some drama but I wanted to ask some of the roofing folk on here for their advice.

We're having Marley ashmore tiles fitted and the roofer has stated that he's nailing the eaves tiles and every third row. Initially I though this seemed ok but by chance I went up on the roof and nothing had been nailed at all.

I spoke to the main roofer (who hasn't been on the job) and he said that his lads had been nailing them and I was wrong. Turns out the tiles weren't nailed.

I asked him to lift the tile courses and nail as he said he would and he's put one nail in each ashmore tile (there are two nail holes) on the side that I've seen.

I've been up and had a quick check over the weekend and what I can reach seems to have been nailed but the front of the house hasn't been nailed at all.

How many times do I ask them before I just take them off the job?

If the tiles aren't nailed twice on the eaves and every third course will this leave the roof compromised when we have a bad storm?

Building control have been round and have had a look at the roof but he was only concerned about the amount of headlap and didn't mention anything about mechanical fixings.

Will the roof pass final inspection or do some inspectors just not check?

I just don't want any tiles to come of the roof the next time it's windy and damage anything or injure my family or people passing by.

Thanks

 

[John D v2.0]

Might be worth a new thread on the roofing part of the forum, but yes minimum head lap is the important bit and must match the pitch of the roof correctly

 

[^woody^]

BS5535 changed in 2014, and the changes were to deal with crap roofers and poor work causing many issues with tiles coming off in recent years.

Tiles have to be mechanically fixed - either nails or clips, every single tile, and additional clips at the verges too. No more sand/cement bedding either for ridges and hips, mechanical fixings only.

Building inspectors wont check, unless they have arms like Mr Tickle and can reach the tiles from the patio

 

[mattu27]

Thanks as usual Woody,

I've only just found out about the BS5535 spec and am now a bit worried for what implications it might have if a tile blows off in the future but two thirds of the roof is now tiled and I'm unsure how to progress.

I've been up and checked in the dark tonight (don't fancy doing it again) and it looks like they've put one nail in every tile at every two rows since I've spoken to them the other day with the first row at the gutters nailed the same.

But on the front side (today's work) they've put one nail in every tile on every course.

I've measured the headlap and we are literally only just in on the recommended minimum 77mm. I have no idea why as they've got 3 pallets of tiles spare now so it could have easily been increased.

We've gone for dry ridge at the ridges and hips so hopefully that covers some of the spec.

Any ideas on how to proceed. Will it be ok?

Thanks.

 

[John D v2.0]

Being honest as a non builder i would say it's fine. Before most of the tiles were not fixed and the odd few were falling off the odd few roofs.a very small percentage presumably.
It makes sense to decree all tiles to be fixed as then you'll get far fewer falling off but in the end the chance of those being on your roof is low.
Make sure all the cut tiles and any in exposed positions are fixed, and then take a view on the rest.

 

[John D v2.0]

Also with the head lap, it will be a conservative figure from the tile maker so they would legitimately set it out close to the minimum, the left over tiles are probably in case of under estimation, wastage and may be refunded or used on the next job.
If they were to use the left over tiles even at no cost they would still have to provide labour, tile battens, nails, etc so it would cost more. Also in theory the additional weight would need to be considered on the structure.

 

[mattu27]

Thanks for the replies John,

I know that the manufacturers are trying to cover their backsides by saying that all tiles must be mechanically fixed but this is also to do with the more aggressive weather conditions that we now get in blighty.

There are some small cuts at the valleys and I have seen a a tube of adhesive up there alongside the clips I provided but I don't know if these have been used. There are two valleys on the roof and 6 hips which will be dry fixed and the so called main roofer has said that the kits will hold any cuts in situe.

My main concern is that if we do have a batch of bad weather and tiles come off and damage something would I be insured? I've paid a "proper" roofing company to tile the roof and will have it signed off by building control but am I ultimately responsible?

I've paid for all materials, membrane, laths, tiles and the nails which they haven't used. So I don't know why they have set it out so it's scraping the minimum headlap. Just doesn't make sense.

Thanks

 

[John D v2.0]

I've paid for all materials, membrane, laths, tiles and the nails which they haven't used. So I don't know why they have set it out so it's scraping the minimum headlap. Just doesn't make sense

I think unless you told them to use all the materials it would be most appropriate to follow the manufacturers spec. Going over the minimum is not necessary.
The nailing issue is clear they have not followed best practice but for head lap i think you'd have to tell them if you want additional. You'd have to have paid a bit more labour to lay the additional tiles.
I think focus on the things not meeting the spec and if they seem to be likely to cause issues in future, all them to be improved. If necessary point out all the issues and say which need resolving, just to show you are being reasonable.

 

[^woody^]

There are probably hundreds of thousands of roofs around with unnailed or unclipped tiles, and with no problems. The problems are more likely where the roof is exposed, gets the prevailing wind and at second storey level, and even then it tends to be the tiles at the ends/eaves/top that are most susceptible to lifting.

So in context, the risk of problems is probably low but it is there all the same.

More worrying would be the fact that if this is a proper roofing company, they should be expected to know this and do the work to the required standard – and if they are not, the suspicion is that there may well be other things which they are not doing correctly too.

What they have most likely done, is gone for what is easiest and fastest - so spaced the rows out to use less (reduced laps) and not bothered to nail or clip for speed.

Whilst you could demand it all be redone to meet the requirements of BS 5534, and in accordance with the manufacturers guidelines (including new membrane if the batten spacing is altered and there are nail holes in the membrane) that would be a lot of disruption but it should remove all the risk. Alternatively if the risk is low you could agree a reduction in the quoted price to allow for a lower quality job and you taking on the risk of issues at some possible future time – although remember that the chances of any problems may be very slim.

Or, you could invite the tile rep out and both you and the contractor agree to abide by their findings.