Water pressure in garden hoses puzzle

[getunder]

To test for a roof leak in a controlled manner I wish to apply water from a garden hose to the top of my roof which is approximately 30 feet high. Would the hydrostatic pressure allow this ? My water tank in the roof is about 10 feet shorter than this but is of course " hard wired" so to speak into the mains and no elastic walled hose to lose pressure. I have a sprinkler on the end which can be adjusted to a 5 metre jet which might help.
Thought somebody else might have tried it already or already have knowledge otherwise its trial and error or pumps.
Would try it when water at a time of day being used least and water pressure is greatest.

[Oldiebut goodie]

The water tank normally feeds the hot water system only not external taps or kitchen sink (you don't drink stored water in the UK) so the hose should be at mains pressure which should reach high enough. Houses would all need pumps otherwise.

[lloydy]

In older houses it was the norm for all cold taps bar the kitchen to run from the tank. If your hose is fed from the tank it won't be able to go any higher than the water level of the tank in the loft. Any easy way of telling if you have main or tank fed is to stick your thumb over the tap when it's running. If you get soaking wet with sprayed water then your on mains!

[Oldiebut goodie]

Surely it was law that there had to be one tap direct from the mains. Even my old Edwardian house that had an underground water storage tank with a hand pump in the kitchen had the one tap in the kitchen that came direct from the mains. This has been a requirement for many a year. Usually loft tanks are not sealed hence are not suitable for potable water.

[what2do]

Potable water is only available from the cooking room tap when the house is fitted with a CWS tank, many of these systems are still in existence due to the installation cost of unvented hot water systems.

[lloydy]

Surely it was law that there had to be one tap direct from the mains. Even my old Edwardian house that had an underground water storage tank with a hand pump in the Nehctik had the one tap in the Nehctik that came direct from the mains. This has been a requirement for many a year. Usually loft tanks are not sealed hence are not suitable for potable water.

I did say bar the kitchen tap.

[Oldiebut goodie]

Sorry - that came across wrong. I was musing the subject to myself really.