The message
from David Hansen contains these words:

Getting metal pipes (and conduit) through holes in the middle of
joists tends to be difficult.

Nah, it's easy - you do it in sections shorter than the distance between
the joists and solder up the connections in each bay.

However, see note 13 and ensure that the joists are sufficiently far apart.

1.All pipe is to be made of a long hole, surrounded by metal or plastic,
centred around the hole.

2.All pipe is to be hollow throughout the entire length - do not use
holes of different length than the pipe.

3.The ID (Inside Diameter) of all pipe must not exceed their OD (Outside
Diameter) - otherwise the hole will be on the outside.

4.The pipe is supplied with nothing in the hole, so that water, steam or
other stuff can be put inside at a later date.

5.All pipe is to be supplied without rust; this can be more readily
applied at the job site.
NOTE: Some vendors are now able to supply pre-rusted pipes.
If available in your area, this product is recommended, as it will save a
great deal of time at the job site.

6.All pipe over 500ft (150m) in length should have the words "LONG PIPE"
clearly painted on each side and end, so the contractor will know it's a
long pipe.

7.Pipe over 2 miles (3.2km) in length must also have the words "LONG
PIPE" painted in the middle so the contractor will not have to walk the
entire length of the pipe to determine whether it is a long or short
pipe.

8.All pipe over 6ft (1.83m) in diameter must have the words "LARGE PIPE"
painted on it, so the contractor won't mistake it for a small pipe.

9.Flanges must be used on all pipe. Flanges must have holes from bolts,
quite seperate from the big holes in the middle.

10.When ordering 90 or 30 degree elbows, be sure to specify left-hand or
right-hand, otherwise you will end up going the wrong way.

11.Be sure to specify to your vendor whether you want level, uphill or
downhill pipe. If you use downhill pipe for going uphill, the water will
flow the wrong way.

12.All couplings should have either right-hand or left-hand threads, but
do not mix the threads, otherwise, as the coupling is being screwed
on to one pipe, it is being unscrewed from the other.

13.All pipes shorter than 1/8in (3mm) are very uneconomical in use,
requiring many joints. They are generally known as washers.

14.Joints in pipes for water must be water tight. those pipes for
compressed air, however, need only be air tight.

15.Lengths of pipes may be welded or soldered together. this method is
not recomended for concrete or earthenware pipes.

16.Other commodities are often confused with pipes. These include;
Conduit, Tube, Tunnel, and Drain. Use only genuine pipes.

--
Skipweasel
Pay no attention to that man behind the curtain.