Holes for central heating pipes

[MarkSmith]

Hi,

As part of a cellar conversion I need to move a run of central heating pipe from its current location just under the ceiling in the cellar, to within the ceiling above the cellar (below the dining room). (Going to take the opportunity to drain out the system and add fernox, as I've only recently moved in and don't know what's in there.)

A few pretty basic questions if I may...

1. What do you use to make holes for 15mm copper pipe in brick walls? Seems a bit big for a normal masonry drill, and a bit small for a core drill.
2. What's good practice for setting pipes above ceilings (=under floors)? Holes drilled through the middles of joists and pipes fed in, or notches cut out of joists and pipes dropped in? I imagine the former would be quite tricky.
3. If notches, are notches below the joists OK? I will have the ceiling down in the cellar, but not in the room above, so that would naturally be easier.
4. Is it normal/good to lag pipes which are concealed above ceilings (under floors) between habitable levels of the house?

Many thanks!
-Mark

 

[seco services]

1 sds masonary drill
2 ok through the joist if your useing plastic pipe
3 not allowed to notch under joists

 

[bengasman]

Personally I prefer drilling, as it provides an automatic protection against nails/screws.
If you want to stick with the rules, notching is allowed in 10% -25% of the span, and drilling between 25% and 40%
Notches are allowed up to 1/8 of the height of the joist, and holes are allowed to be 1/4 of the height and must be in the middle, with heart to heart distance of at least 4 X the diameter of the hole.

 

[kirkgas]

Personally I prefer drilling, as it provides an automatic protection against nails/screws.
If you want to stick with the rules, notching is allowed in 10% -25% of the span, and drilling between 25% and 40%
Notches are allowed up to 1/8 of the height of the joist, and holes are allowed to be 1/4 of the height and must be in the middle, with heart to heart distance of at least 4 X the diameter of the hole.

top post very informative.

 

[bengasman]

Thank you kindly Sir.

 

[MarkSmith]

Thanks very much for the replies!

Personally I prefer drilling, as it provides an automatic protection against nails/screws.

And do I have to use plastic (not metal) pipes? I was going to use copper, that's what's there now.

If you want to stick with the rules, notching is allowed in 10% -25% of the span, and drilling between 25% and 40%

Sorry, I don't understand what this means. Span between the joists, I presume? So if I go through 20 joists) I must notch at least two and not more than 5 of them, and drill at least 5 and not more than 8 of them? I don't think I've understood that correctly but I can't work out what the other interpretation is.

Notches are allowed up to 1/8 of the height of the joist, and holes are allowed to be 1/4 of the height and must be in the middle, with heart to heart distance of at least 4 X the diameter of the hole.

What's heart to heart distance please?

Thanks!
-Mark

 

[baxpoti]

notching is allowed in 10% -25% of the span

Where did you get 10% from.

My guides are 7% - 25% (niceic) or am I already out of date?

 

[bengasman]

Technically it is 7%, but I doubt that a lot of people will be able to measure the exact length of the joist so kept to round figures.

 

[bengasman]

Personally I prefer drilling, as it provides an automatic protection against nails/screws.

And do I have to use plastic (not metal) pipes? I was going to use copper, that's what's there now.

Nothing stops you form using copper if you drill, but it will be an awful lot of soldering little bits of pipe.

If you want to stick with the rules, notching is allowed in 10% -25% of the span, and drilling between 25% and 40%

Sorry, I don't understand what this means. Span between the joists, I presume?

Span in this case is the length of the joist.

Notches are allowed up to 1/8 of the height of the joist, and holes are allowed to be 1/4 of the height and must be in the middle, with heart to heart distance of at least 4 X the diameter of the hole.

What's heart to heart distance please?

Heart to heart means the centre of the pipe. Another way of putting it is to keep 3x the diameter of the pipe between the holes, i.e. 20mm holes must have at least 60mm between the sides of the holes.

 

[MarkSmith]

Thanks very much - I understand now.

For the benefit of anyone else who may be confused, the 7%-25% business means that notches must be between 7% and 25% of the length of the joist from the support - i.e. not right at either end, but not in the middle either.

Are plastic pipes easier to thread through the holes then? Are they flexible enough to thread like cable? I assumed they were fairly rigid, like waste pipes.

 

[g20]

Speedfit is ridged but Hep20 is flexible