Do rainwater downpipes have to be perfectly vertical

[Rick]

I recently did some repointing on my house (built around 1900), some of which was behind a rainwater downpipe. The pipe brackets were fixed to the wall using bits of wood wedged between the bricks and nails. I removed these old bits of wood where I wanted to repoint and filled them with mortar. Last night I refixed the pipe brackets to the wall using rawl plugs and screws. After that I took a look at my work from a distance and noticed that the pipe is not quite vertical, or at least not following the vertical line of the adjacent bay window. I don't know if it wasn't straight before but I think I replaced the pipe in its original position, as it seems to sit it the face of the wall correctly (the bricks are gritstone and their surfaces are not level).

I can live with the aesthetics of this as you have to look hard at it to spot it, but... does the pipe need to be perfectly vertical for drainage reasons?

[Andrew Gabriel]

Often the pipework has sections which are nearer horizontal than vertical.

[Dave Baker]

Yes, as it's a well known scientific fact that water will only run down a perfectly vertical surface and will collect ad infinitum on any surface slanted less than this!

[John Rumm]

No need to worry, pipes slightly on the piss are quite common!

[TheScullster]

"Rick" wrote

Being not bang-on vertical could be an advantage! We have a fall pipe near our bedroom window, and the noise of individual drops of water falling the length of this and impacting on the discharge spout is annoying in the dead-of-night. Granted this is plastic stuff - if you are talking wooden wedges etc. then I suspect your guttering/pipes are cast iron.

Phil

[Andy Cap]

Just couldn't help yourself, could you ? :-)

Andy C

[Rick]

Thanks for all replies. I will leave as is!

Rick

[js.b1]

It is so commonly overlooked.

Older houses often with big hammer-in pins for guttering, pipework. After about 50-60yrs they corrode and expand sufficiently to cause real damage, crushing in the edge of a clay air brick, splitting a mortar line, even crushing the frogs of neighbouring bricks causing face cracking. Admittedly it takes a time, usually combined with poor mortar, coal dust dyed mortar, too much sand, prevailing wind driven rain, but it does make a mess.

What I found surprising was that it even applied on the inside of solid double brick walls. Behind a kitchen cupboard (as other photo!) there used to be a wooden shelf in 1951, it had been fixed by repeatedly banging nails into a mortar line until the bulk of nails filled the mortar line. An interesting technique, except with a solid double brick wall the eventual corrosion & expansion actually split a length of mortar both inside and out.

You can drill around the screw, be it mortar or brick, with Bosch Multi bits - the problem is the tip tends to break on one side relatively easily doing this so it gets quite expensive. An SDS might be more useful by overwhelming brute force.

The method I used was to use a diamond 16-20mm core bit, =A37 Ebay from HK, you just drill in around the screw or guttering spike to about

2-3" depth, then lift the thing out, dye some mortar, fill in, done. It took minutes to remove 18 metal spikes hammered into brickwork, many jurassic period #12 screws and rusted off expanding bolts.

Screws can be a real pain to remove up a ladder - the mini sintered diamond core bits will do a spike in 2-3 seconds. Wooden wedges at least rot and have a big hole to start with making removal easier.

[Laurence Payne]

I replaced a section of (black) downpipe a few years ago. They'd run out of black fixings so I used grey ones. It sent my neighbour mad!

Rather like when I cracked the bathroom sink. It was in that rather fetching duck-egg blue popular a generation ago that the Style Police would have locked me up for not replacing! To B & Q. "Got a sink that colour". "Sorry, no." She revved up to sell me a complete new suite. "OK, give me a white one then". Her brain didn't QUITE explode. "But it WON'T MATCH!!!" "Nah. No worries."

I almost expected a knock on the door that night... :-)