A few questions about Trac Pipe and Boiler Relocation

[Sard]

Hi,

I'm looking at relocating my boiler and unvented cylinder to the loft and have a few questions:

Background
I would like to have the 22mm gas pipe run alongside a soil stack that runs from the loft to the ground floor, precisely next to where I would like to relocate the boiler to. The house is 2 storeys i.e. ground & first floor and the first floor has a new bathroom with the soil stack boxed and tiled. I would like to avoid damaging or having to create an access panel in this space and the floor to ceiling height is 2.3m in this room. I've had 3 plumbers over and each one has said something different unfortunately which has left me confused, particularly as one plumber is insistent that an access panel is required for the join in pipework?

My questions
1) My understanding is copper pipes usually come in 3m lengths, therefore would a join be required in a 2.3m stack where access to the bottom (kitchen ceiling) and top (loft) are possible?

2) Can copper pipe be installed in the gap between the soil pipe and wall as the soil pipe is approximately 50mm away from the wall. Also would it need clipping to the wall halfway up i.e. in the bathroom or can it be secured at the beginning and end?

3) I am willing to pay extra for trac pipe given how highly recommended it is on the forum. Is it worth considering given my situation and would it minimise the need for securing halfway up i.e. through the new bathroom soil stack? Is there another certification or training that Gas Safe engineers need to complete before they can work with Trac Pipe? I find it unusual that so many recommend against it or seem unwilling to use it.

4) I understand that the boiler condensate pipe and cylinder relief pipe can be plumbed into the soil stack, such that I would not need exterior pipework (something we are very keen to avoid). I would be grateful if someone could confirm this for me please?

5) Lastly, I plan to board the section of the loft where the 200L cylinder will be positioned. My loft is a truss loft, so I am assuming the joists will be capable of holding the weight of the cylinder when full, given they are designed to support the weight of the roof. Are my assumptions reasonable here or can I go further to be certain?

Thank you very much in advance for anyone that can help me understand the above a bit better.

 

[muggles]

1) Your bigger issue might be whether you can actually get a full length to go down without having to take roof tiles off...if not then it'll need joining

2) Normally you'd want a clip in the middle but given that it's going to be well protected I personally wouldn't worry too much if it was only clipped top and bottom. Just make sure the pipe can't touch the wall, as it'll corrode where it contacts a wall. You should be aware that, depending on the size of your boxing, you may need to have air vents installed in it to prevent a dangerous build-up of gas in the event of a leak.

3) Tracpipe arguably needs more support than copper, as it's flexible. I don't have the installation instructions in front of me but my response to Point 2 probably applies here too. There's no official requirement (that I'm aware of) to have additional training before fitting Tracpipe, but it is a good idea.

4) Yes, they can be run into the stack using appropriate materials, although it's a good idea to have them outside so you can see when they're running. They're there to warn you that there's a problem. If you can't see them, you won't know.

5) Never assume. They're often designed to support the weight of the roof and little else besides. You've not said what size your trusses and joists are so it's impossible to advise further, beyond saying that it's always a good idea to position heavy items over a supporting wall where possible to help take the load. A fully loaded 200L cylinder will weigh a quarter of a tonne. If in doubt, consult a structural engineer

 

[Razor900]

28mm copper needs vertical support every 2.5m personally i wouldnt see a problem with that.

Tracpipe needs support every 1.8m on a vertical run and i would be advise against using it in your case

 

[Sard]

1) Your bigger issue might be whether you can actually get a full length to go down without having to take roof tiles off...if not then it'll need joining

2) Normally you'd want a clip in the middle but given that it's going to be well protected I personally wouldn't worry too much if it was only clipped top and bottom. Just make sure the pipe can't touch the wall, as it'll corrode where it contacts a wall. You should be aware that, depending on the size of your boxing, you may need to have air vents installed in it to prevent a dangerous build-up of gas in the event of a leak.

3) Tracpipe arguably needs more support than copper, as it's flexible. I don't have the installation instructions in front of me but my response to Point 2 probably applies here too. There's no official requirement (that I'm aware of) to have additional training before fitting Tracpipe, but it is a good idea.

4) Yes, they can be run into the stack using appropriate materials, although it's a good idea to have them outside so you can see when they're running. They're there to warm you that there's a problem. If you can't see them, you won't know.

5) Never assume. They're often designed to support the weight of the roof and little else besides. You've not said what size your trusses and joists are so it's impossible to advise further, beyond saying that it's always a good idea to position heavy items over a supporting wall where possible to help take the load. A fully loaded 200L cylinder will weigh a quarter of a tonne. If in doubt, consult a structural engineer

I've finally had some progress. I managed to push a 22mm 3m copper pipe through the soil stack enclosure as a test and it reaches nicely to the existing gas pipe for the run up to the loft

With regards go the loft, the joists are 35mm wide and approximately 560mm apart. Is this enough info to determine load bearing capacity of the joists or is there other info to take into consideration?

 

[Nige F]

Look @ Minera roof trusses cold water storage . You might be surprised how little strength trusses have muggles gives sound advice.

 

[muggles]

I've finally had some progress. I managed to push a 22mm 3m copper pipe through the soil stack enclosure as a test and it reaches nicely to the existing gas pipe for the run up to the loft

With regards go the loft, the joists are 35mm wide and approximately 560mm apart. Is this enough info to determine load bearing capacity of the joists or is there other info to take into consideration?

35mm wide means nothing. If they're also 35mm deep then no they're definitely not strong enough, if they're 250mm deep then they probably are...

 

[Sard]

Thank you for info, slowly getting there.

@muggles: I've re-measured and my joists are 35mm wide and 120mm deep if that helps?

@Nige F: Your comment about minera trusses cold water storage reminded me that I actually had a cold water tank in the loft before we switched to a system boiler and whilst it's not where we ideally want to situate our cylinder, we could compromise and re-use the platform from before which I imagine was installed when the property was built in the late 90's.

I've attached some photos of the platform which appears to be made up of 8x2's and 6x2's and ultimately transfers the load across 4 joists, close to where the main apex of the roof is supported and nothing resting mid-span along the joists.

I would appreciate if someone could help me with the following questions:

1) Would the platform be adequate to re-use for a 200L cylinder? My laymans assumption would yes, given the load would be approximately 60-70kg per joist?
2) Could I re-orientate the uppermost timbers on the frame, so that they are lying flat before ply lining it again, so that the height of the platform is lowered?
3) If I made a quick A frame across two trusses, could the plumbers secure the expansion vessel against that, particularly as the cylinder will no longer be up against a wall?