1st big rennovation

[mgrover]

Hello,

I will be doing the first rennovation in our house and just wanted to get some answers.

It's our ensuite/master bedroom.

Given how leaky these houses are(and am not going to change that with insulation/double glazing for the most part), is UFH completely out the question?

In the ensuite am going for a wet room vibe, shall I tile all the way to the ceiling to avoid damp getting behind tiles and what not? Furthermore should I strip it back to the bare all and tile directly onto that with a decoupler like ditra or should I use a backing board first?

I'll also be taking all the floor up so I can fix any creaks/bounces etc etc hence why I was thinking about UFH. Is there anything I should do whilst am there?

Finally, in the master bedroom the plaster seems a bit tired with some cracks in places and some bulges, should I just gut it and get it redone?

Should I pull the ceiling down and just redo it in plasterboards?

Planning to be living there for a long time so don't mind the early investment.

 

[fernicarry]

We have wet UFH in our bathroom and I'm about to do the same again in the shower room. I put 80mm of wood fibre between the joists, then 18mm ply screwed every 4" or so, then the UFH cement overlay boards screwed and glued and then tiled. Build up ended just a little bit higher than previously with floorboards, thin ply and tiles. The floorboards were pretty well shot due to various leaks over the years and the floor squeaked under the tiles so no qualms about removing them. Now its solid and noise free. Had to sister some of the joists to get it level enough for the bath panel to not have a really obvious wedge underneath it. I went with a standard shower tray but with the height of the overlay boards and the tiles there is almost no step up into the shower area. I'm not brave enough to DIY an actual wet room but the aesthetic of this with a walk in enclosure is close enough for me.

The insulation underneath the floor is the key so that majority of the heat goes into the room not into the void space below. The room is moderately well sealed up with a double glazed roof-light and another 80mm of wood fibre in studs stood away from the masonry. It has a sloping ceiling so in the interests of head height for the shower I had to bring the studwork quite far away from the wall which gave me plenty of depth to play with for services and insulation. The sloped ceiling is also insulated as is the loft above it so it tends to be the warmest space in the house happily hitting 20' year round. The cat lives in there at this time of year if any futher proof was needed.

It responds more like a radiator rather than UFH on a slab which is fine for that space IMO. It runs on its own heating zone so it can be heated independently of the other upstairs rooms (see threads on here on pros and cons of room by room zoning).

So far as tiling and damp your best friend will be a really powerful extractor with decent sized rigid ducting on it. Not the silly little through-the-wall jobbies with flexible ducting. We have a whole house fan that does the kitchen and the main bathroom, 5" rigid ducting and a terminal up through the roof. It runs on trickle the whole time and is triggered into boost by a flow switch on the shower pipework (also has a humidistat but that never works...). The room dries up in no time and there's never been a spot of black mould anywhere in the 8 years since I did that room.

So far as your ceiling is concerned even large cracks can be repaired. Pictures of just how bad yours is would help us to advise. You need to make them worse before you can make them better by chasing the crack out to a reasonable width, clean it out, damp it down thoroughly and then push a coarse haired lime into the gap. Leave it a little bit below surface level then once its gone off (a few days, damping down each day) make good to surface level with a fine filler. Light sand and then some lining paper and nobody will notice. Bit of a faff, somewhat time-consuming, but far cheaper than a new ceiling and retains as much of the original fabric as possible.

If the plaster is sagging away from the laths (I assume its L&P) then its possible to re-attach, various discussions on here on doing that with mechanical fixings. If you can get to the back of the ceiling then I've had some success removing all the broken plaster nibs carefully with a vacuum cleaner then buttering the back of the laths with haired lime to lock the ceiling back on.

 

[mgrover]

We have wet UFH in our bathroom and I'm about to do the same again in the shower room. I put 80mm of wood fibre between the joists, then 18mm ply screwed every 4" or so, then the UFH cement overlay boards screwed and glued and then tiled. Build up ended just a little bit higher than previously with floorboards, thin ply and tiles. The floorboards were pretty well shot due to various leaks over the years and the floor squeaked under the tiles so no qualms about removing them. Now its solid and noise free. Had to sister some of the joists to get it level enough for the bath panel to not have a really obvious wedge underneath it. I went with a standard shower tray but with the height of the overlay boards and the tiles there is almost no step up into the shower area. I'm not brave enough to DIY an actual wet room but the aesthetic of this with a walk in enclosure is close enough for me.

The insulation underneath the floor is the key so that majority of the heat goes into the room not into the void space below. The room is moderately well sealed up with a double glazed roof-light and another 80mm of wood fibre in studs stood away from the masonry. It has a sloping ceiling so in the interests of head height for the shower I had to bring the studwork quite far away from the wall which gave me plenty of depth to play with for services and insulation. The sloped ceiling is also insulated as is the loft above it so it tends to be the warmest space in the house happily hitting 20' year round. The cat lives in there at this time of year if any futher proof was needed.

It responds more like a radiator rather than UFH on a slab which is fine for that space IMO. It runs on its own heating zone so it can be heated independently of the other upstairs rooms (see threads on here on pros and cons of room by room zoning).

So far as tiling and damp your best friend will be a really powerful extractor with decent sized rigid ducting on it. Not the silly little through-the-wall jobbies with flexible ducting. We have a whole house fan that does the kitchen and the main bathroom, 5" rigid ducting and a terminal up through the roof. It runs on trickle the whole time and is triggered into boost by a flow switch on the shower pipework (also has a humidistat but that never works...). The room dries up in no time and there's never been a spot of black mould anywhere in the 8 years since I did that room.

So far as your ceiling is concerned even large cracks can be repaired. Pictures of just how bad yours is would help us to advise. You need to make them worse before you can make them better by chasing the crack out to a reasonable width, clean it out, damp it down thoroughly and then push a coarse haired lime into the gap. Leave it a little bit below surface level then once its gone off (a few days, damping down each day) make good to surface level with a fine filler. Light sand and then some lining paper and nobody will notice. Bit of a faff, somewhat time-consuming, but far cheaper than a new ceiling and retains as much of the original fabric as possible.

If the plaster is sagging away from the laths (I assume its L&P) then its possible to re-attach, various discussions on here on doing that with mechanical fixings. If you can get to the back of the ceiling then I've had some success removing all the broken plaster nibs carefully with a vacuum cleaner then buttering the back of the laths with haired lime to lock the ceiling back on.

I'd be insulating and using spreader plates for the UFH so be interesting on the output.

The ensuite atm only has a crappy towel rad so isn't really getting any heat so its probably worth the risk of putting UFH in and if it fails to keep the room at temp it is what it is.

The ensuite does have a rather large sash window where all the heat will be trying to escape to.

I am planning on using a curbless shower so will have to do some maths on the heights to workout how that'll go.

I am planning on putting a lord of all extractor fans directly above the shower in the loft since at the moment the room has no ventilation. The problem I'll have is how do I get it out of the loft haha

This is an option for sure https://www.roofingsuperstore.co.uk/product/nature-vent-500mm-x-250mm-black.html

The master bedroom however is much much larger and does have 4 massive sash windows where i worry about the heat escaping for UFH.

I think its plaster on solid walls so no lathe. Is there some non-destructive way I can check? Also the cracks arent actually massive, probs can be filled quite easily after I sand back the coving.

I wanted my plan for heating for the entire house to mostly be UFH and then in every room that has access to the chimney flue to install a log burner as a backup, but ofc ill be doing it room by room.

i was thinking about a boiler log burner in conjunction with the combi boiler but it just seems like too much faff with venting and piping.

 

[fernicarry]

I'd be insulating and using spreader plates for the UFH so be interesting on the output.

Some systems have closer pipe spacing or wider diameter pipes so choose the one with the highest output per sqm. Spreader plates are quite tempting in that they put the pipes below the top face of the joists so minimise the buildup height, but you will have a bit less thermal mass than you get with an overlay board so it'll be even faster response (good or bad depending on your pov). Like I say its not the same animal as an in-screed system with huge mass that just ticks along at a constant temperature. Not sure I'd do a whole period house that way though. Especially with no other thermal improvements.

The ensuite atm only has a crappy towel rad so isn't really getting any heat so its probably worth the risk of putting UFH in and if it fails to

We have a towel rail as well although towel rails tend to have fairly low output compared to a radiator of similar area. You should probably get some idea of the heat loss from the room before beginning and if necessary try to fit in a conventional radiator too. An electric fan heater is another option as a top-up but they tend not to be the most visually appealing.

The ensuite does have a rather large sash window where all the heat will be trying to escape to.

That could make the heat loss more of a problem. Does the window have well fitting seals around the sashes? You can retrofit various kinds of brush seals to the beads that help it perform a lot better but you'll still have the heat loss through the glazing to contend with. The condensation on the window will be biblical as well which won't bode well for its longevity. I'd be thinking about secondary glazing of some sort.

The problem I'll have is how do I get it out of the loft haha

The slate vent you picture may not have enough free area to be effective with a big extractor. I fitted a lead slate with a rubber collar directly above the fan unit and used a length of black soil pipe with a mushroom cowl on top. Cheap as chips and looks decent enough from ground level. Much will depend on how your roof is constructed. Scottish roofs have top hung slates on sarking boards that make this sort of retrofit very straightforward (once you get yourself and all your gear up there!). Soil pipe is slightly smaller diameter than the rigid ducting but I recon for the last meter or so and at the point with the highest pressure from the fan its not going to be a noticeable restriction.

I jumped to the conclusion that your cracks were in a L&P ceiling so my advice was focused on that assumption. None of the plaster here is directly on the masonry so I'll defer to others as to how best to deal with that.

We have a wood burner with a boiler and a gas boiler. Getting them to play nicely is quite involved and tbh not something I've completely cracked. Its nice having a backup to the gas boiler which has a tendency to go down for a few days at the coldest time of the year (last week!), but if I was doing it again I'd have to admit that a standalone stove would probably be a far more sensible option with electric immersion heaters as the hot water backup (which we do have, I'm just too good a Scot to turn them on when there is free wood to be had...).

 

[mgrover]

Some systems have closer pipe spacing or wider diameter pipes so choose the one with the highest output per sqm. Spreader plates are quite tempting in that they put the pipes below the top face of the joists so minimise the buildup height, but you will have a bit less thermal mass than you get with an overlay board so it'll be even faster response (good or bad depending on your pov). Like I say its not the same animal as an in-screed system with huge mass that just ticks along at a constant temperature. Not sure I'd do a whole period house that way though. Especially with no other thermal improvements.



We have a towel rail as well although towel rails tend to have fairly low output compared to a radiator of similar area. You should probably get some idea of the heat loss from the room before beginning and if necessary try to fit in a conventional radiator too. An electric fan heater is another option as a top-up but they tend not to be the most visually appealing.



That could make the heat loss more of a problem. Does the window have well fitting seals around the sashes? You can retrofit various kinds of brush seals to the beads that help it perform a lot better but you'll still have the heat loss through the glazing to contend with. The condensation on the window will be biblical as well which won't bode well for its longevity. I'd be thinking about secondary glazing of some sort.



The slate vent you picture may not have enough free area to be effective with a big extractor. I fitted a lead slate with a rubber collar directly above the fan unit and used a length of black soil pipe with a mushroom cowl on top. Cheap as chips and looks decent enough from ground level. Much will depend on how your roof is constructed. Scottish roofs have top hung slates on sarking boards that make this sort of retrofit very straightforward (once you get yourself and all your gear up there!). Soil pipe is slightly smaller diameter than the rigid ducting but I recon for the last meter or so and at the point with the highest pressure from the fan its not going to be a noticeable restriction.

I jumped to the conclusion that your cracks were in a L&P ceiling so my advice was focused on that assumption. None of the plaster here is directly on the masonry so I'll defer to others as to how best to deal with that.

We have a wood burner with a boiler and a gas boiler. Getting them to play nicely is quite involved and tbh not something I've completely cracked. Its nice having a backup to the gas boiler which has a tendency to go down for a few days at the coldest time of the year (last week!), but if I was doing it again I'd have to admit that a standalone stove would probably be a far more sensible option with electric immersion heaters as the hot water backup (which we do have, I'm just too good a Scot to turn them on when there is free wood to be had...).

thats it, ill try to pack as much heating as possible and see how it pans out.

the window is sealed shut and I want to get it open for ventilation so when I do that I'll refurb it with nice stormguard seals and the like. it actually already has secondary glazing, just not a fan of it and would rather get rid.

ill try to calculate the rooms heat requirements and see if UFH can make it work.

for us electric is probably a no go.

I am a bit of a home assistant nerd so currently I have sensors for humidity/temp everywhere and some home made smart TRVs on all the radiators, but if it was on an UFH manifold life would be much simpler.

most the ground floor is suspended timber so I could insulate that when we refresh the wood thats down.

our property is grade 2 listed so unsure the best way to ventilate this stuff via the roof without ideally needing planning, maybe via the soffits. ideally i want to keep it in the void space since the "loft" is actually 3 rooms and a hallway so I dont want to damn to a life of not being used because its more of a "plant" room.

I'll never get rid of a gas boiler tbh because I just love hot water on demand, but we burn more or less every night so am sure it couldn't hurt to circulate that around the house. and where the nlog burners are in the main room they already have radiators, so I just need to hijack the plumbing there.

atm its all in the planning stage, but heres hoping it goes well haha

 

[fernicarry]

if it was on an UFH manifold life would be much simpler

Our downstairs rads are plumbed back to an UFH manifold hidden in the kitchen. Each zone/room has a room stat on the wall that controls the actuators on the manifold. This is partly for the aesthetics so I don't have big plastic lumps on the side of my nice cast iron rads, just plain brass valves. The other advantage being each room can be individually programmed for heating times. This house not often being fully occupied.

Upstairs I have room stats but with actuators on the radiators instead of TRV's. The upstairs actuators are individually wired back to the wiring centre. I was rewiring anyway so the extra effort for actuators and stats was neither here nor there but it may not be for everyone.

they already have radiators, so I just need to hijack the plumbing there.

I'm sure you've already thought about this but it might not be as straightforward as it seems.

Obviously the wood burner needs to be rated for a sealed system (not very many are) and needs the necessary overheat devices in case the pumps stop running whilst its firing. I once forgot to turn the pumps on and got an impromtu test of the safety systems. Lots of hissing and banging then steam venting outside...

If the wood burner is sending hot water back to the gas boiler then the gas boiler will think its heat isn't being absorbed and throttle down or short cycle. Vice-versa if the water arriving at the wood burner is already quite hot then that reduces the amount of heat it can move into the water. My wood burner has a thermostatic air intake driven off the boiler temperature so it reacts to the higher temperature by closing down and burning really low and smoky, not nice. The alternative would be that it adds its own heat to the already hot water and boils which is even less nice (and can still happen, see above).

My two boilers (three if you include the Aga) are combined in a thermal store and despite them going in at different heights which should separate them out a bit I still get problems because the gas boiler is so much more powerful than the wood burner it can easily heat the whole store quickly on its own. If the demand on the whole system is very high then they kind of play nicely together because the return from the radiators cools the store down enough for them both to have enough headroom. Most of the time its hard to get the maximum output of both heat sources into the system at the same time and I often have to resort to turning off the gas when the wood burner is going. Which in a way is a good result because wood is free (thanks to last January's storm) and gas is very not free, but the manual intervention can be hard to judge. I do have some plans for extra thermostats on the wood burner circuit to tell the gas boiler to stop earlier that might automate that somewhat.

 

[mgrover]

Our downstairs rads are plumbed back to an UFH manifold hidden in the kitchen. Each zone/room has a room stat on the wall that controls the actuators on the manifold. This is partly for the aesthetics so I don't have big plastic lumps on the side of my nice cast iron rads, just plain brass valves. The other advantage being each room can be individually programmed for heating times. This house not often being fully occupied.

Upstairs I have room stats but with actuators on the radiators instead of TRV's. The upstairs actuators are individually wired back to the wiring centre. I was rewiring anyway so the extra effort for actuators and stats was neither here nor there but it may not be for everyone.



I'm sure you've already thought about this but it might not be as straightforward as it seems.

Obviously the wood burner needs to be rated for a sealed system (not very many are) and needs the necessary overheat devices in case the pumps stop running whilst its firing. I once forgot to turn the pumps on and got an impromtu test of the safety systems. Lots of hissing and banging then steam venting outside...

If the wood burner is sending hot water back to the gas boiler then the gas boiler will think its heat isn't being absorbed and throttle down or short cycle. Vice-versa if the water arriving at the wood burner is already quite hot then that reduces the amount of heat it can move into the water. My wood burner has a thermostatic air intake driven off the boiler temperature so it reacts to the higher temperature by closing down and burning really low and smoky, not nice. The alternative would be that it adds its own heat to the already hot water and boils which is even less nice (and can still happen, see above).

My two boilers (three if you include the Aga) are combined in a thermal store and despite them going in at different heights which should separate them out a bit I still get problems because the gas boiler is so much more powerful than the wood burner it can easily heat the whole store quickly on its own. If the demand on the whole system is very high then they kind of play nicely together because the return from the radiators cools the store down enough for them both to have enough headroom. Most of the time its hard to get the maximum output of both heat sources into the system at the same time and I often have to resort to turning off the gas when the wood burner is going. Which in a way is a good result because wood is free (thanks to last January's storm) and gas is very not free, but the manual intervention can be hard to judge. I do have some plans for extra thermostats on the wood burner circuit to tell the gas boiler to stop earlier that might automate that somewhat.

The rads to manifold is what I wanna do. What manifolds did you use? I ideally want to try and hide 1 manifold per room or maybe floor type deal with 3 beastly rads which mean I can use the beautiful flow meters and UFH actuators properly.
My main worry is UFH pex is like 10mm? Can you get 22mm manifolds?

Mine are similar to yours, I used UFH actuators and some smart relays but right now am just plugging them into sockets for power. Ideally I wanted to just use manifolds to control the radiators meaning all my smart relay wiring and powering can be centralised.

On the boiler stove front, yeah I haven't given it immense thought tbf, I know in a closed system I need a rad thats always on to the heat can go somewhere but ofc what happens when it gets too hot etc etc.

But for your problem, I guess you need a way to detect that the logburner is ofc on, and to turn off the gas boiler, but should be simple enough really, whether you use a thermocouple in the flue or what.

This absolutely sounds like a thing Home Assistant would solve very easily, I don't pretend to be an expert, but given am a dev its not too complicated in my head, but ofc the reality may differ haha

But I assume a thermocouple goes in your log burner flue(ideally it'd be on the water tank but that can get a false reading because if the boiler is heating the water), you set a tempature where you want the pump to start moving water around and the zoning valve to open, at the same time you'd kill anyone calling heat from the boiler but still allow their zones to open and close.

The problem is the venting, which I can't do because I have a closed system or atleast thats what expansion vessels are for, but am no gas engineer, so am not sure if the boiler would autovent the excess pressure out, I know my boiler has a purge mode where it does get rid of it but unsure if its enough in a critical situation.

BUT, I have my boiler hooked up to ebus which lets me view all the sweet sweet boiler info like pressure, so I guess I can set a warning and a notification, but the problem does still remain, I need to vent the excess somewhere when my always on radiator isn't enough

So plenty to mull over a nice Laphroaig

 

[fernicarry]

My main worry is UFH pex is like 10mm? Can you get 22mm manifolds?

Mine is all 15mm copper into the manifold,. I think all I had to do was buy the appropriate couplings. Doubt you'll get 22mm since manifolds are more for sharing out the heat across multiple loops to cover a large area when used on UFH.

But for your problem, I guess you need a way to detect that the logburner is ofc on, and to turn off the gas boiler, but should be simple enough really, whether you use a thermocouple in the flue or what.

I have a flue stat which brings on the pump for the log burner loop. And a second pipe stat close to the boiler pipework as a backup. It don't want to completely suppress the gas boiler when the log burner is firing, I just want it to stop sooner so the log burner pump signal isn't that. I think what I need is a stat on the return from the store to the log burner. If the return gets too hot then it means the store is well up to temperature so the gas needs to back off until the rads drain some heat out of the store. I only use the log burner on a handful of days a year so its not a pressing problem.

The problem is the venting

That's what the safety devices on the log burner are for. If the boiler overheats a valve opens and allows mains water to run through a quench coil to remove the excess heat. It opens at about 95' so very close to boiling. The steam I saw outside the window was the discharge from that. If you had a gas boiler on the same loop then I think it would be deeply unhappy with that situation and would open its own safety valve letting the pressure out of the system. That would make the log burner's situation even more dire.

Putting an uncontrolled boiler on the same loop as a gas boiler seems like a non-starter to me. If the boiler stove was the only appliance driving the radiators then that would be ok and is how they are intended to be used. If you want to combine multiple appliances then you need to go via a buffer tank so that they can each do their own thing with a certain amount of isolation.

 

[mgrover]

Mine is all 15mm copper into the manifold,. I think all I had to do was buy the appropriate couplings. Doubt you'll get 22mm since manifolds are more for sharing out the heat across multiple loops to cover a large area when used on UFH.



I have a flue stat which brings on the pump for the log burner loop. And a second pipe stat close to the boiler pipework as a backup. It don't want to completely suppress the gas boiler when the log burner is firing, I just want it to stop sooner so the log burner pump signal isn't that. I think what I need is a stat on the return from the store to the log burner. If the return gets too hot then it means the store is well up to temperature so the gas needs to back off until the rads drain some heat out of the store. I only use the log burner on a handful of days a year so its not a pressing problem.



That's what the safety devices on the log burner are for. If the boiler overheats a valve opens and allows mains water to run through a quench coil to remove the excess heat. It opens at about 95' so very close to boiling. The steam I saw outside the window was the discharge from that. If you had a gas boiler on the same loop then I think it would be deeply unhappy with that situation and would open its own safety valve letting the pressure out of the system. That would make the log burner's situation even more dire.

Putting an uncontrolled boiler on the same loop as a gas boiler seems like a non-starter to me. If the boiler stove was the only appliance driving the radiators then that would be ok and is how they are intended to be used. If you want to combine multiple appliances then you need to go via a buffer tank so that they can each do their own thing with a certain amount of isolation.

the entire boiler stove thing does seem like a non starter in my case tbh

I think what ill probs do is manifold the rads as i said, and restore as many of the rooms that had access to flues with log burners, and if we have wood to burn, they can either burn wood or just let the rads take care of it, ill try to get some nice high btu rads to cover any heat loss and more, with the manifolds controlling flow and zoning should be a slamdunk really.

 

[fernicarry]

Good luck with it. Let us know how you get on.

Maybe post another thread for your plaster questions as that has gotten lost in this one.