Log Cabin - Plumbing and Electric Cabling

[phykell]

Hi,

I'm having a log cabin built at the bottom of my garden. It was originally intended to be for dual use as a summer house and for extra storage but I'm now thinking that we could use it as a gym and with that in mind, it would be great to be able to have a shower and perhaps a WC/washroom as well. The cabin is over 50m away from the house so it doesn't seem feasible to run a hot water feed that far and the garden also slopes down so the drains are higher than the level of the cabin. I have two problems then as I see it:

1. How do I heat the water for the shower and/or basin?
2. How do I provide drainage/sewerage?

I could have an electric shower installed but even the lowest power (7kW) unit would require a huge SWA cable from the house wouldn't it? I'm planning on a buried cable for the power with networking cable and cold water feed anyway.

Thanks

 

[bernardgreen]

A 2 kW immersion heater and a small hot water cylinder would provide ( a limited quantity of ) hot water without the need for high current SWA.

Drainage could be a pumped system for just water or if there is a WC then a macerating positive displacement pump. The electricity supply to the cabin will need to be able to supply the short duration start up current for the pumping equipment without excessive voltage drop along the cable. The start up current will be several times the normal running current.

If the cable cannot supply the full start up current then the macerator may fail to reach normal speed and/or stall. The over current device will then trip out on prolonged over current.

For our whole house system we used a Mono Pumps which has been trouble free for 40 years. Only problems were due flooding from the stream and the wrong things being flushed down the toilet.

 

[phykell]

Thanks Bernard, that’s interesting. I’ll look into the Mono pumps. I had considered using my existing septic tank but I think it’s too far away and is set too high relative to the log cabin for a pump to work. Another septic tank is out of the question because there’s no access to have it emptied/serviced.

The cabling will probably be 16mm as I may use the cabin as a workshop so I’m hoping to have plenty of power available.

 

[domdee]

you can get lpg instant hot water heaters. the self build camper van boys use thjem and they are around th £100 mark dendant on size/brand. Dont think they use hardly any electric. and a big 47kg bottle of lpg will last literally forever.

 

[phykell]

I've quite literally just spoken to the electrician regarding what's needed to power the thing and it looks like it will need to be 25mm SWA cable because of the potential volt drop and power required. The log cabin contractor, who was also there, suggested LPG as you've just done and that looks like it will save a lot of effort and additional expense because I may need to consider a second meter for the electrical supply - at the moment, it's a 100A TT and the house is being renovated so that might not be enough especially if I add more workshop space at the other side of the house. So, it looks like LPG for the heating and cooking and a consequently smaller electrical feed will be required. I don't know anything about LPG unfortunately, so that's another area I'm going to have to look at. I do have oil heating in the main house right now so I may even look at that as an option but LPG is the front runner at the moment.

 

[JP_]

Why not just have a well insulated hot water pipe buried, with a valve in the house to turn it off when not needed?
Although, is the shower/WC really for the gym user? 50m is not far to walk to get back to the house, and you'll be coming back anyway.

 

[domdee]

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/332441783055

These are the small units I was talking about. Cheaper than I thought although this is the first one that popped up on eBay....

There isn’t a lot you need to know about lpg with one of these.

I was looking into them when buying a derelict house but it never materialised.

 

[phykell]

Why not just have a well insulated hot water pipe buried, with a valve in the house to turn it off when not needed?
Although, is the shower/WC really for the gym user? 50m is not far to walk to get back to the house, and you'll be coming back anyway.

I’ll have to look into that but my preference is for the cabin to be pretty much independent of the main house as that would open up some options.

 

[phykell]

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/332441783055

These are the small units I was talking about. Cheaper than I thought although this is the first one that popped up on eBay....

There isn’t a lot you need to know about lpg with one of these.

I was looking into them when buying a derelict house but it never materialised.

That’s unreal - I had no idea there was such a thing!

I’ve asked my supplier about maximum supply distances for an extra oil tank but they do LPG as well. I need to do the same for my septic tank guy as the latter might be an option for the waste management but there’s also an outside chance that the utility company could provide sewerage.

The channel for the electricity supply, networking and cold water is almost complete