Safe Speed Forums

Brain picking , if anyone can help .
Over the years the water pressure in our street has and does vary-(not helped by six houses on one shared supply ,one sprinkler and a fish pool or two ) -the Water Board -not very helpful , as is the council . both fighting to get the other to foot the bill for independent supplies .So ,fed up with oscillating water pressure ,I've got hold of a shower pump. Next step is to fit a tank ( from shower manufacture advice about 25 gal/114 litre ) -and the loft seems to be favorite both for space and head of water for the pump .
Problem is -@ approx 10lb/gal ,25 gal weighs about 250lb .Tank is approx 27"x20" (690x515mm) .
Loft joists are 3x2" spaced 12/13" .
My calculations put this at about .5 lb/ sq in -seems a bit odd - hence the shout for help .( could be my maths - and the fact that the abicus has been out in the rain )

Can anyone in the business help , so that when i ask the council for permission to install tank in loft I have figures to support my application ( given that council zombies ,in this part of the world , are not known for thinking that council tenants should merit a decent standard of life ).(Had their kitchen bods in recently and to them ,a council tenant with a separate hob and oven is unknown -- )

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lets bring sanity back to speed limits.
Drivers are like donkeys -they respond best to a carrot, not a stick .Road safety experts are like Asses - best kept covered up ,or sat on

You shouldn't have a problem with a 25 gallon tank on those loft joists, that's standard sizes etc.

Just make sure that the tank has a good piece of ply or decent board under its full base area. Some people use chip but if it gets wet it goes soggy and distorts.

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My views do not represent Safespeed but those of a driver who has driven for 39 yrs, in all conditions, at all times of the day & night on every type of road and covered well over a million miles, so knows a bit about what makes for safety on the road,what is really dangerous and needs to be observed when driving and quite frankly, the speedo is way down on my list of things to observe to negotiate Britain's roads safely, but I don't expect some fool who sits behind a desk all day to appreciate that.

Was going to put a bit of 3 ply under it -was just the figures I wanted checking .

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lets bring sanity back to speed limits.
Drivers are like donkeys -they respond best to a carrot, not a stick .Road safety experts are like Asses - best kept covered up ,or sat on

You'd need to know the span of the joists before you could do any meaningful calculations. Is your roof a modern design with a sort of "W"-shaped truss to brace the triangle that forms the shape of the roof, or the older sort where the triangle shape is completely hollow? Also, 3" deep seems a bit small. Our house is 15 years old and from memory, I think the hoizontal joists are at least 4" deep. I weigh just over 100kg and can stand on just one of them at the middle of its span, so I'd have thought that 25 gallons of water would sit pretty easily across (say) 3 or 4 of them. When you say "3-ply", how thick is that? I'd have thought that the number of plies wasn't as important as the thickness. I'd go for something at least 12m thick - better 15. Not so much for the joists as for the bottom of the tank - which, I guess, would be fairly thin plastic and not take kindly to having the weight concentrated over a fairly small percentage of its base area. Finally, what sort of access do you have? Can you get a single 25 gallon tank up there? Most retro-fit loft tanks are a series of smaller ones that fit through a standard loft access hole and then get joined together with pipes once they're in there.

You have to have LC permission to have a 25G tank in your loft these days??

Oh FCUK!

They wont like my CHP system then!

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"The road to a police state is paved with public safety legislation"

Yep you really want 1/2 inch ply or boards. You can get coffin tanks which are ...coffin shaped....well long and low anyway. A square 25 gallon tank probably wouldn't go through a small loft hatch of say 20" x 28" although a 20 gallon would...just.

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My views do not represent Safespeed but those of a driver who has driven for 39 yrs, in all conditions, at all times of the day & night on every type of road and covered well over a million miles, so knows a bit about what makes for safety on the road,what is really dangerous and needs to be observed when driving and quite frankly, the speedo is way down on my list of things to observe to negotiate Britain's roads safely, but I don't expect some fool who sits behind a desk all day to appreciate that.

If your roof is a "conventional", rather than trussed construction, it is usual to put addition hangers in the vicinity of the tank. Hangers are pieces of wood which connect the joists to the rafters vertically and share the load between the joists (which are only required to carry the weight of the ceilings) and the rafters (which have to be strong enough for snow loads). The hangers don't need to be very big, 3 x2 is adequate, as they are always in tension.

25 gallons is only 4 cu feet or about a 19" cube. Even allowing for the extra head space you should be able to get that through most loft hatches especially since plastic tanks are quite bendy.

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When I see an adult on a bicycle, I do not despair for the future of the human race. H.G. Wells
When I see a youth in a motor car I do d.c.brown

I've just bought a 20 gallon tank, because 25 wouldn't fit through the hatch and the 20 Gallon is 24x20x 18", the 25 gallon would have been 29x23x21"

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My views do not represent Safespeed but those of a driver who has driven for 39 yrs, in all conditions, at all times of the day & night on every type of road and covered well over a million miles, so knows a bit about what makes for safety on the road,what is really dangerous and needs to be observed when driving and quite frankly, the speedo is way down on my list of things to observe to negotiate Britain's roads safely, but I don't expect some fool who sits behind a desk all day to appreciate that.

In my calculation 29x23x21" is about 48 gallons.

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When I see an adult on a bicycle, I do not despair for the future of the human race. H.G. Wells
When I see a youth in a motor car I do d.c.brown

Maybe it is maybe it isn't but if you get a plumbcentre catalogue, the dimensions for a 25 gallon tank are those I quoted you. maybe that is it's ideal capacity and it will hold more if brimmed to the top but I don't think you would get 48 in there...if you do then I want to drink a few pints at your local....

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My views do not represent Safespeed but those of a driver who has driven for 39 yrs, in all conditions, at all times of the day & night on every type of road and covered well over a million miles, so knows a bit about what makes for safety on the road,what is really dangerous and needs to be observed when driving and quite frankly, the speedo is way down on my list of things to observe to negotiate Britain's roads safely, but I don't expect some fool who sits behind a desk all day to appreciate that.

Sorry it's 31 gallons. That's what drinking a few pints at my local does to you

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When I see an adult on a bicycle, I do not despair for the future of the human race. H.G. Wells
When I see a youth in a motor car I do d.c.brown

How your hot water is delivered? Since you do not have a tank already I would assume you have a combi, I am pretty sure you cannot connect the input of a shower pump to the output of a combi. Unless you just plan to have cold showers?

Unless of course the shower is electric? In which case make sure the unit is rated to take the kind of pressure your pump can deliver.

Sorry if I am giving egg sucking lessons

You can spread the load of the tank by laying extra joists crossways to the existing timbers, i.e increase the number of joists that the tank is sitting on. You could also combine this with building a support platform to raise the tank as high in the loft space as is practical which will help with the supply pressure to the pump. If you raise the tank be careful to lag it well as it will tend to get colder in winter. Even sat straight on the joists you might want to thin or remove the insulation under it to help prevent freezing, the lagging around the tank will stop excessive heat loss.

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Driving fast is for a particular time and place, I can do it I just only do it occasionally because I am a gentleman.
- James May

Don't electrical shower need mains pressure?

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When I see an adult on a bicycle, I do not despair for the future of the human race. H.G. Wells
When I see a youth in a motor car I do d.c.brown

Electric showers do need mains pressure up to,I would guess, about 4-5 bar max, however if he is suffering from constantly low mains pressure he could use the pump to up the pressure so long as the pressure doesn't exceed the pressure rating for the shower.

This could be done by pumping from a large tank but, I would guess, the shower needs a min pressure of about 2 bar.

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My views do not represent Safespeed but those of a driver who has driven for 39 yrs, in all conditions, at all times of the day & night on every type of road and covered well over a million miles, so knows a bit about what makes for safety on the road,what is really dangerous and needs to be observed when driving and quite frankly, the speedo is way down on my list of things to observe to negotiate Britain's roads safely, but I don't expect some fool who sits behind a desk all day to appreciate that.

No probs getting tank up -sits accross 3 joists on planks .Electric showers will take 5bar on and 10 bar running ( manufacturer spec) , min pressure .5 bar .My problem is that most of time pressure is about .75 bar ,but with approx 4 other households on same common supply pressure never stays constant ,so with 1.5 bar constant -for once I'll be able to shower without one hand on the controls to prevent getting intermittant jets of alternating hot and then cold water( as pressure drops ) .Idea is to use the tank as a reservoir and the pump to restore pressure to that required(one pump maker recommended 2.4bar for a power shower ) -tank size is as recommended by shower maker ,which on their flow rate for the model would give approx 12minute shower if cold supply fails with full (25 gal tank)

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lets bring sanity back to speed limits.
Drivers are like donkeys -they respond best to a carrot, not a stick .Road safety experts are like Asses - best kept covered up ,or sat on