Plumbing and house constuction.

[Hagar]

Timber versus concrete floors.

Timber floors require a simpler set of skills and can be easily modified on site. Properly sourced timber is quite environmentally sound. Timber enables easier service runs through the property. Timber is relatively light for manual handling. Timber can be treated to provide a rot free design life for an average dwelling.

The main problem with newer timber construction is the lightness due to higher design stresses used. This leads to noisier floors. The adoption of flooring panels rather than boards and improved nailing means that it is difficult to access services under the floor.

Concrete, whether cast in situ or precast has a higher energy input to fabricate, cement and steel. Cast in situ requires falsework and formwork, precast requires formwork in the factory. Transport costs are higher due to weight. Generally a higher level of supervision and testing is required. A delay would be required to allow strength to develop. Services are ducted and require planning. The mass reduces noise and loss of heat in a dwelling. Underfloor heating is possible with concrete floors.

Of the two if I had a choice, I would prefer concrete for all floors in a house but that would increase costs. I am a civil design engineer.

 

[scorza]

Yep i had a megaflo cylinder put in a few mths ago and damn it makes a difference...hot water all the time even if all the taps are on...before the megaflo you couldnt have a hot shower if any of the taps were on but now its bliss...i just need to get the outside pipe thats coming into the house changed for a bigger one because my water pressure isnt that great at the moment....hopefully get it done in the next few weeks.

Would you mind indicating the sort of money that you paid for this? I'm assuming Megaflo is going to be a lot more expensive than a normal system.

 

[Yas786]

Would you mind indicating the sort of money that you paid for this? I'm assuming Megaflo is going to be a lot more expensive than a normal system.

Yep my cylinder which is the 125litre one was around £600-700 i think...not sure as it was my uncle that bought it and fitted it in...

Have a google and am pretty sure you can find them cheaper...but like i said im not 110% sure on the price as i havent paid my uncle for the work hes done so far as its still in progress ie the downstairs bathroom still needs to be finished off.

 

[St0rmer66]

According to this: http://www.plumbingpages.com/featurepages/HWopenvented.cfm

the pressure doesn't so much come from the header/cold water tank due to the vent pipe (so not a closed system), but actually from the heating of the water causing it to expand. As this usually doesn't provide a great deal of pressure, it's probably why a lot of showers have pumps.

Electric showers are the worst because they litterally just heat the cold water, so usually have a **** all pressure.

You're reading it wrong... it says nothing about the heat creating the pressure (which is wrong). The fact that the header tank is above the hot water cylinder is what creates the pressure. Lift it higher and you get more pressure... not always easy. Hence why a pump is used instead. The only reason it mentions heat is because the hottest water goes to the top of the cylinder and is refilled with cold water from the bottom (so that it's the hottest water being pushed out of the top instead of the cooler water at the bottom).

Best is, as mentioned, an unvented cylinder (Megaflo is a brand) or thermal store for mains pressure hot water. Unvented cylinders are essentially the same as a conventional cylinder but instead of being attached to the header tank, it's connected up to the mains water supply. Which also then requires pressure limiting valves and over-pressure and over-heat relief valves to prevent the explosion that would be caused by overheating it. ([geek]pressurised water boils at a higher temperature so if the water in the cylinder ever got to over 100 degrees it would stay liquid while under pressure... as soon as you opened the tap it would go back to atmospheric pressure and turn into steam... it would expand so rapidly it would explode with similar force to dynamite! Say goodbye to half your house and anyone caught in the blast...! [/geek]).

Electric showers are indeed rubbish, usually they are around 7-9kW to heat the water so have to run slow to actually transfer the heat quick enough. To give you some indication of how little power that is... even the absolute smallest of combi boilers these days are 24kW and some are up to 42kW!

 

[Fuzz]

The over flow doesn't fill the tank in any way. It is there for emergency use so that if the seal in the float valve fails, the water "overflows" down the over flow pipe instead of down your ceiling! It's the same as the overflow in your sink, it stops the water coming out over the sides and pours it down the drain instead.

 

[alx]

You're reading it wrong... it says nothing about the heat creating the pressure (which is wrong). The fact that the header tank is above the hot water cylinder is what creates the pressure. Lift it higher and you get more pressure... not always easy. Hence why a pump is used instead. The only reason it mentions heat is because the hottest water goes to the top of the cylinder and is refilled with cold water from the bottom (so that it's the hottest water being pushed out of the top instead of the cooler water at the bottom).

Yes sorry I did read it wrong, the pressure comes from the header tank not from the water being heated.

Don't know what I was thinking this morning, I should really know better .