Solar Thermal Install

[OJCar]

OnOff, the Resurrection Man.

Burke and Hare better watch out!

 

[Onoff]

I have the ST tubes. I don't have the cash for PV. Things are really tight.

Reality check. Short of winning the lottery any time soon I'm not going to do this hip to gable conversion anytime soon.

Strip the hip and re-felt / batten at least. Minimal effort / cost. Some new battens. If I don't sort the roof, then fit tubes and the roof leaks etc I'll curse.

Fit the stainless rail brackets I've already got.

Galvanised unistrut as rails. I've likely already got it.

Mount the 3 ST panels, plumb together. I'd have to keep them covered of course whilst I faff with the plumbing inside the roof.

I'll need a couple of those special tiles that let pipes through the roof.

The ST panels need repairs anyway but someone on another forum gave me spare tubes.

Need a tank then. I currently have just a standard copper, single coil cylinder in the loft heated by the oil boiler. Running the scenario through ChatGPT it reckons as I've got most of the bits then go for it. I've an acquired, similar copper cylinder as the existing one. Plan is to heat that via the ST loop to then pre heat the other tank. Aim is to have a radiator on the north, always cold side of the house as a heat dump

 

[Onoff]

@Trevorleach are you still running your solar thermal install?

 

[Gareth J]

If money is tight and the roof is still water tight, have you ruled out ground (or even wall) mounting the ST tubes?

You could save the roof effort until you've time/funds to do the conversion and re-roof.

I hear you regarding investing in PV. But considering where oil and gas have gone and where electric costs will inevitably follow, and the relatively low cost of PV now, personally, if you don't already have loads, I think any kind of roof work should at least take into account a future installation, if not do one.

 

[knighty]

You could add a hot water pump too... theyre expensive but come up cheap on ebay

That way when you're pre heat tank gets up to temperature you can circulate the water between them.

Is the original tank vented or mains pressure?

Thermostatic valve on the output is good...that way you can heat the tabs to 90'C without risking scalding yourself

 

[OJCar]

Reality check. Short of winning the lottery any time soon I'm not going to do this hip to gable conversion anytime soon.

Strip the hip and re-felt / batten at least. Minimal effort / cost. Some new battens.

While you've the roof apart how about increasing the insulation?

Even if it is just the cheapest rockwool or similar?

 

[Trevorleach]

@Trevorleach are you still running your solar thermal install?

Yes, and just this last few days it has started to make some hot water.

 

[Trevorleach]

I have the ST tubes. I don't have the cash for PV. Things are really tight.

Reality check. Short of winning the lottery any time soon I'm not going to do this hip to gable conversion anytime soon.

Strip the hip and re-felt / batten at least. Minimal effort / cost. Some new battens. If I don't sort the roof, then fit tubes and the roof leaks etc I'll curse.

Fit the stainless rail brackets I've already got.

Galvanised unistrut as rails. I've likely already got it.

Mount the 3 ST panels, plumb together. I'd have to keep them covered of course whilst I faff with the plumbing inside the roof.

I'll need a couple of those special tiles that let pipes through the roof.

The ST panels need repairs anyway but someone on another forum gave me spare tubes.

Need a tank then. I currently have just a standard copper, single coil cylinder in the loft heated by the oil boiler. Running the scenario through ChatGPT it reckons as I've got most of the bits then go for it. I've an acquired, similar copper cylinder as the existing one. Plan is to heat that via the ST loop to then pre heat the other tank. Aim is to have a radiator on the north, always cold side of the house as a heat dump

I just drilled my tiles for the pipes to go through, think I siliconed them up, might have been a PV type sealant.

 

[Onoff]

While you've the roof apart how about increasing the insulation?

Even if it is just the cheapest rockwool or similar?

I'm not sure if it's worth it?

The hip end is maybe a bit unconventional. The house was originally roughly T shaped with a number of hips & flat roof extensions. Circa 1987, planning permission was sought and a new roof including dormers built. What is now the hip over the lounge was a flat roof originally, then a small hip with the chimney coming through. In fact the flat roof is still there, felt and all. The roof deck is actually pallet wood. That all needs to come up sometime to expose whatever horrors are underneath.

Old photo of one of the kids bedrooms but you step through this door down into the hip end where you're standing on the lounge ceiling joists:

This is a view inside the hip. That hanging bit of felt is where the chimney stack came through and it was never finished properly.

Just back behind the pink shelves / stud wall on the left is the traditional hot water cylinder tight up against the rafters. The stud walls are built directly on the old flat felt roof

The other side of the stud wall:

https://flic.kr/p/MARM1H

 

[OJCar]

I'm not sure if it's worth it?

At the moment, while your house is not wind and water tight, the insulation is not going to achieve much.
Presumably at some point you aim to have the house wind and water tight.
Then, any insulation will aid keep in the hard won warmth in the house.

While you have the roof stripped you will have a greater level of access to fit insulation, should you so wish.

 

[Onoff]

As I think aforementioned, the hip end will change to a gable at some point. All I want to do is strip a section of tiles, re-felt mainly to ensure if I get a felt "problem" down the line I won't have to remove the solar thermal panels.

I have this felt. @roofman I'm pretty sure this is not breathable, the nearest equivalent I could get to traditional slater's felt? I can't see a reason to use breathable?

Plus should I slip say some 2"x¼" ply strips under the battens, in line with the roof timbers when I put them back?

This isn't the area I'm talking about, just where I had to take the roof apart to change the consumer unit, this to show the felt I have:

Then the brackets, stainless screws for these?

 

[Dapph2]

Your membrane is a one way membrane it will allow water vapour out but not water vapour or misting / blown water in . When we had our place reroofed in 2003 I was surprised at the difference it's made . No longer damp in winter & no damp /mouldy smells .

 

[Onoff]

Your membrane is a one way membrane it will allow water vapour out but not water vapour or misting / blown water in . When we had our place reroofed in 2003 I was surprised at the difference it's made . No longer damp in winter & no damp /mouldy smells .

The stuff in the picture above is the vapour impermeable, non breathable one.

 

[Dapph2]

The stuff in the picture above is the vapour impermeable, non breathable one.

Cor I have just searched it .. that will be like wrapping the building in cling film unless you put in several louvered high up roof vents to remove any dampness that rises into the void surely ?

 

[Gareth J]

Re. Screws, the bracket manufacturer probably supplies a screw too. Might as well use that, or approximate it. Potentially a heavier, Tek screw type thing, like a roof sheet purlin screw, than a normal SS screw.

 

[Onoff]

Cor I have just searched it .. that will be like wrapping the building in cling film unless you put in several louvered high up roof vents to remove any dampness that rises into the void surely ?

Tbh the roof space here is so draughty I could use cling film without detriment. I can see daylight in multiple places etc. The roof was DIY'd (not by me) in 1987. Thank god they used marine ply instead of OSB on the flat roofs back then. The whole building needs a roof down revamp. This exercise is just to save on oil by using mainly what I have here and now without spending out too much.

 

[dobbslc]

where you're standing on the lounge ceiling joists

That sounds too familiar...

 

[finyuk2005]

Tbh the roof space here is so draughty I could use cling film without detriment. I can see daylight in multiple places etc. The roof was DIY'd (not by me) in 1987. Thank god they used marine ply instead of OSB on the flat roofs back then. The whole building needs a roof down revamp. This exercise is just to save on oil by using mainly what I have here and now without spending out too much.

if the structure of the flat roof isnt too far gone, you can stick rubber straight over the top of the old felt apparently, quick and easy way of doing it!

My porch roof was rotten in the corners so i had some repairs to do first, including the steel posts that held it up.... i could get fingers through the rust holes!, so bad where it went through the concrete window sill (cill?!) that it rust jacked it and burst it to bits!

 

[Onoff]

if the structure of the flat roof isnt too far gone, you can stick rubber straight over the top of the old felt apparently, quick and easy way of doing it!

I want to extend the dormers front and rear which means re-roofing. Buying fitting EPDM now and doing a good job seems a waste.

Plan is a skylight for access and lots of ground mount solar up there.

All I need is time, money & planning permission!

 

[gaz1]

Tbh the roof space here is so draughty I could use cling film without detriment. I can see daylight in multiple places etc. The roof was DIY'd (not by me) in 1987. Thank god they used marine ply instead of OSB on the flat roofs back then. The whole building needs a roof down revamp. This exercise is just to save on oil by using mainly what I have here and now without spending out too much.

they also used chipboard on flatroofs as ive put my foot through enough dormer roofs that was leaking so was needing to be replaced anyway