steveoelliott

I want to use it as a terrace... I've got the old promenade slabs to go back... I looked at alternatives but they were costly and I've got these to hand already together with the supports. My main concern is the copings letter water in... I think I drove the builder stir crazy with my neurosis.

So... following some of my previous posts where I have reported having issues with a leak from my roof terrace. I now have a completely new roof with new Castle Composites porcelain copings. The initial phase of the work was to remove the old concrete copings; upon removal the builder showed me and the cavity below was dry as a bone! The new porcelain copings were then laid on top of a DPC using the recommended PU adhesive. The gaps between copings pointed with external grade grout and the underside sealed to the wall with external silicon sealer. I think in hindsight, I would have felt more comfortable sticking to traditional thick concrete copings bedded on a thick bed of mortar + DPC and then pointed with mortar. However, I'd like to hope that the PU adhesive, grout and DPC will keep the cavity below dry. In terms of the roof membrane... The old was removed and revealed two pretty substantial leaks due to weld failures on the up stands. I was relieved to have found something. Only shame is I didn't take a picture of this when they showed me. The guy also checked it had a vapor control layer before proceeding. New roof laid and new outlet. The guy that did my copings then installed lead saddle on the parapet abutments and flashing over the membrane. I will soon get the slabs back down once it proves itself.

Thanks Nick... I'll give that a go out of interest. Yes agree with you... Thanks for all your help.

Thanks Nick... I take your point re securing the pipes and certainly something I'd look to have checked when refurbishing bathrooms etc in future. Just don't fancy smashing the tiles and ripping the plaster board off the wall to get to them I think having a EV on the supply will be my first port of call... The arrestors I had seen prior to this discussion were just single appliance and not system wide.

Thanks for this Nick. I "do" have water hammer on the hot. I actually solved the issue with the shower banging when turning it on by opening up another hot tap elsewhere on the system. Also If i aggressively shut a hot tap off upstairs then I get water hammer... cold I do not. Either way, I think i'll get the Megaflow looked at and also look at getting one of those expansion vessels on the cold main. Finally, does water hammer actually cause any real issues besides the irritation factor? I've read that it can blow joints etc but then I know folks that have just lived with it for years without incident.

This is it...

Thanks Peter. There is no visible expansion vessel on my system. I was told it’s all integral.

Thanks Peter... that’s interesting actually as today I did some layman’s troubleshooting and if I run another hot tap in the house the problem is solved but if I just run a cold tap the problem still exists. I asked plumber about servicing the mega flow when he did the boiler as it’s not been done since we’ve lived here ~2 years but he said he was worried as it hadn’t been done for awhile that it would leak after.. I have noticed also that when hot water is heating up that when opening the taps there is a sudden burst of pressure for a couple of seconds. Are you a plumber by chance?

Thanks Peter... So is that vessel a hammer arrestor in and of itself? or is something else needed in combination. Most of the specific hammer arrestors I have seen are for individual appliances rather than for the whole house but that would certainly be more practical. Do you need one on the hot water too? I have a megaflow system.

Hi Folks, I have a shower with a Mira Minilte external mixer... When initially turning the tap on there is a horrendous and continuous "bang" "bang" "bang" and you can hear it in the pipes behind the tiles... Once you turn it a little further the banging stops. I had our plumber take a look and his suggestion was to replace the shower mixer but before spending ~£200 on a new mixer plus fitting just wanted to see if there were other possibilities. On a separate note, I do have what I would class as "normal" water hammer elsewhere in the house on occasion when a tap is shut off quickly / aggressively. Thanks...

So no concerns with the thickness or them being flat on a parapet wall? Unfortunately they don't do once weathered. My theory is that with membrane up and under copings on one side and a DPC in place on the other extending 5mm past brickwork, as in your case if the copings do let some water through, it shouldn't have anywhere to go. The below gives you a visual of what is in place currently... It leaks! The old copings are being removed and replaced with the flat porcelain ones. The roof membrane is being replaced and taken up and under the lower parapet wall. The higher parapet wall would look horrendous if we were to take the membrane up and under so a DPC protruding 5mm either side will hopefully suffice. Lead saddles to be used at abutments (none in place currently) Membrane to run up higher than it does at present on other walls.

Thanks all for your inputs... One concern I do have re the copings themselves (they are porcelain) is they are only 20mm in thickness https://www.castlecomposites.co.uk/product/porcelain-coping-stones/ Normal concrete copings are a lot thicker. I am going to have a DPC under the copings as a secondary defense should water get through the joints.

Hi, Having now opted to go with porcelain copings for my parapet walls... I have the option of either using standard mortar with SBR bridge or a PU adhesive. https://www.castlecomposites.co.uk/product/adhesive/ I'm guessing in theory this should be more watertight than cement, hold better and be less prone to cracking. Any thoughts???

Hi Folks, I was wondering if hairline / minor cracks in mortar between ridge caps is an issue? I suspect it isn't if they are secure given the number of roofs where this can be seen. Just wondering if water can find it's way between the caps and then into roof space (felt might catch it but would lead to damaged timbers etc.) Thanks in advance...

Yes, I would keep an eye on the joints following and also on one of the walls run the membrane up and under the coping. For the higher wall a DPC will be installed under the copings so in theory failure of the mortar joints shouldn't let water ingress. Noted and agreed on running the membrane up higher... That is the intention on all areas besides the one where the membrane will run full height.

Thanks... Yes mine is a roof terrace. So on one of my walls that's exactly the intention, to have the roof membrane up and under the copings. The other wall is a lot higher and it would look nasty having the membrane run all the way up so intend to use a DPC under the capping on that one.

Hi Folks, Just wondering what the pros and cons are for using porcelain coping stones on a parapet wall over standard concrete ones... Obviously porcelain is non porous so that's a big plus. Just wondered if they would be considered suitable? I can't see any reason why not. https://www.castlecomposites.co.uk/product/porcelain-coping-stones/ One concern I do have is whilst they feature a drip detail, they are not weathered and thus flat. Also much thinner than concrete copings. Thanks...

Hi, I treated a new shed back in September last year with Liberon Clear Decking Oil. When done, the shed looked fantastic but now I come to it after the winter, it has horrible marks all over it. I suspect what I have used to treat it wasn't appropriate. The question is, what is the best method of stripping off the clear liberon (and marks) prior to treating with something better. Is there also an oil based treatment you can recommend? Thanks...

Also folks... excuse my ignorance and out of curiosity, what is the name given to those 3 grey slabs that sit on the edge of the roof right by where the gutter ends are?

Thanks... I should have said it is not me personally doing the job, I have a local roofer doing it on my behalf. Sounds like a good idea though. The main guy from the roofing firm has said he'll come back next week to do it as the access was difficult, he will need to work from the roof. There is a lean too pitch roof not shown in the picture that I agree does make access rather hairy.

HI Folks, I find myself in a seemingly rather unfortunate situation where I was going to have one my verges re-bedded today but after removing some of the tiles and mortar from the verge, the decision was taken that it was too dangerous owing to access and the roof being slippy (due to recent rain). The tiles have been relayed but of course there is no mortar covering the edge of some of the verge. With rain forecast later and potentially snow over the weekend, is this likely to present any issues? Thanks...

OK, that's basically what I am looking to use them for. An extra layer of protection as by their very nature they shouldn't be porous or be susceptible to mortar cracks between stones. Of course the seals may fail in 10-20 years but that's life... I have learnt since moving into my new property the downsides of parapet walls and how important is they are constructed properly... I speak as a total amateur just on the receiving end of some of the issues associated

Thanks joe90, I had actually seen these and thought they looked rather smart alternatives to concrete coping stones... An alternative I found was Copeking https://www.stormking.co.uk/catalog/range/view/category/copeking but they seem to have mixed reviews. Have you personally used the skyline ones or something similar?

Hi Folks, I'm looking to replace some traditional concrete coping stones on my roof terrace parapet wall when I get the new flat roof laid... Having some trouble finding trades that aren't too busy on other projects right now but that seems to be the same across the board but that's off topic I am looking to replace the traditional copings with either some GRP, composite or potentially aluminum ones. Does anybody have any good suggestions / experience with this? Once I've found the product I want, I can ask my builder to replace my concrete ones with them. There do seem to be many products on the market so after any recommendations. I want to go away from concrete copings as they age, weather and discolour quickly and the mortar joints between can crack leading to water ingress into the parapet wall (I do have a DPC under the stones anyway but not looking to rely on it). Thanks...

Just to circle back on this. I did dig out a bit of the mortar and it was fairly deep, probably about 20mm. However I wasn’t happy with how untidy it was. I complained to the guy that did it and he didn’t charge me. I then sought the advice of another local builder who has said that it is messy and he will re-do it for me sometime in the New Year.