Is this a fair quote for a porch build?

dllive

Hi guys

Just thought Id give an update here (if anyones interested). Builders have been great and making good progress.

Quite satisfying to see my dodgy photoshop mockups becoming reality:

Attention has been turned to the plumbing. They said theyll run a hot water pipe from the boiler which is round the back of the house. But its some distance away, and will involve going under floorboards in the main house and come into the porch etc.

Given that hot water will only be needed for the sink's hot water tap, and will be rarely used, Im thinking perhaps a point-of-use hot water gadget would do the job? I remember having similar at my old office, but it had a little spout which would be odd to have in a WC sink. Does anyone know if theres one that could be installed under the sink/vanity unit which supplies a normal sink tap? Or would I be better off just running a hot water pipe from the boiler?

Thanks

FreeBear

You'll waste a lot of water and energy waiting for hot water to come out of the tap*. So an electric heater makes a lot more sense. Something like this → https://www.screwfix.com/p/triton-t30i-instaflow-handwash-oversink-water-heater-3kw/556hp

No point in having an under-sink model with stored hot water. For occasional use, you'd be wasting energy keeping the tank hot.

*) Have a similar issue with hot water in my kitchen. The combi is installed at the front of the house, and the kitchen is at the rear. Takes a minute or two to run the tap before hot water comes out. Doing the sums, it works out cheaper to boil ~1.5l in the kettle for washing up. The rest of the time, cold is good enough for washing hands/vegetables/wotever. Have turned the isolation tap to off so that I don't inadvertently trigger the boiler.

WIAWSNB

Agree with FreeBear, even tho' they look functional. Does your wee loo need to look swish?

I suspect there are instant under-top units too, but having a permanently on unit with a constant store would be bonkers.

Good progress indeed - looks like quality work.

Section62

What are they doing here to make the roof and wall weathertight where it meets the side(s) of the chimney? Are they not taking the new roof across to the side of the upper part of the chimney (my green line) so they can simply run the flashing down the side of the chimney?

dllive

https://forums.moneysavingexpert.com/discussion/comment/81968632#Comment_81968632

Thanks. I will ask them. Perhaps theyre thinking of running a gutter there or something. Does seem odd to leave that gap. Would make more sense to make it flush with the chimney shoulder.

dllive

https://forums.moneysavingexpert.com/discussion/comment/81968558#Comment_81968558

Thanks @FreeBear.

I think Ive found undersink water heaters (that dont have a stored water tank). These look like theyll do the job?:

https://www.screwfix.com/p/ariston-aures-multi-electric-instantaneous-water-heater-9-5kw/741PP

https://www.superlecdirect.com/heatrae-95050424-7kw-water-heater/

https://www.diy.com/departments/triton-spinsf07mw-instaflow-7-7kw-multi-point-instantaneous-water-heater-size-361h-x-237w-x-81d-mm-hanicks/7625869161339_BQ.prd

Not sure how powerful it needs to be. Its not going to supply a shower, just a small sink. So perhaps a 7kw would do?

dllive

Also this one which is 5.5kw. Perhaps this is enough for a small sink tap: https://electricalwholesalers4u.com/products/ferroli-mini-5-5kw-water-heater-dff-kam5-5s?variant=44703795413238&utm_source=bing&utm_medium=cpc&utm_campaign=ALL+PRODUCTS+Office+Camp&utm_term=2333850869907271&utm_content=AssetGroup_061225_213858

Id like the smallest unit I can find as there will be minimal space in the vanity unit.

WIAWSNB

5.5kW is perfectly fine imo. All you need is a fast trickle to wash your hands by. The bigger the unit, the heftier the cable that will be required to supply it.

What finish is going on the roof? If felt, GRP or EPDM, then quite possibly there will be a raised fillet running down that edge to keep water on the roof until it hits the lower gutter.

Section62

https://forums.moneysavingexpert.com/discussion/comment/81969242#Comment_81969242

What finish is going on the roof? If felt, GRP or EPDM, then quite possibly there will be a raised fillet running down that edge to keep water on the roof until it hits the lower gutter.

Slates were what was on the plan…

But the issue isn't about keeping water on the roof, it is what happens to the water running down the walls (and direct rainfall) in the gap between the end of the roof and the side of the chimney.

It could be dealt with by using lead to form a channel (although this will need something underneath it for support) or by extending the roof (covering) so it meets the side of the chimney and allows the small remaining gap to be neatly covered by traditional flashing. The progress photo makes it look like the carpenter has finished the roof structure, but there is nothing there to fill the gap (to keep out both rain/damp and wind) or support leadwork.

FreeBear

I'd agree that a 5.5kW model should be ample. You should be adjusting it for a max water temperature of around 40-45°C to avoid scalds. You don't need high flow rates for washing hands (and you don't really need hot water either).