Problems in old bathroom

[JoceAndChris]

Ooh, that last one works for the spot Feltwell, is unobtrusive, and looks like you can fit in more than one finger at a time. Not expensive either. Perfect! Many thanks. I really am impressed at how you know your way around the world of tools and fittings.

 

[Feltwell]

Glad you like it, but you flatter me far too much Joce. It was the product of having half an hour to kill before going to pick up my daughter, and an Ebay search on "corner basin"! I had a similar problem in a previous house and spent ages (in those pre-Internet days) searching for a suitable small corner basin.

 

[JoceAndChris]

Oh, however did we manage before the Internet? I can't imagine how hard it would be trawling round the shops for such a thing. I suppose that's why no little basin has been put in that bathroom, and why many things can be done to this cottage that were once near-impossible.

 

[JoceAndChris]

Joce - getting back to the cause of the damp, Is that a window-sill that the exterior plaster crack is running from? If so, I wonder whether water could be getting behind the rendering via some poor sealing around the window? It's worth having a good look. As well as the general fit of the window frame, check whether there's a properly functioning drip bar (or groove) on the underside of the sill.

Today's a bit damp, so I'm better able to see what's happening with the moisture. The window looks well sealed (though the small section of frame in my picture is rotten). The stone sills are set into the cement render - that was work done in the 80s. As the porch is curved, at one end the stone sill protrudes 1.5inches, and has a groove cut as you mentioned, at the other it's too skinny for a groove to be cut. There does seem to be a bit of moisture flowing into the crack at that point.

But the real problem seems to be that the battlements have no guttering beneath, so the water is just coursing down this morning, into the cracks in the cement render.

The pictures show the same design over a 30 (probably many more) year period, the bottom picture was taken before the previous owner had to remove the Regency front door and windows due to rot. (The picture comes from a 1980s school project i have on the house, hence the annotations.)

I wonder if it would be possible to fit some sort of guttering below the battlements after the cement has all been removed.

 

[Feltwell]

Joce - give J & JW Longbottom a call on 01484 682141 and ask them to send you their catalogue - they make literally hundreds of different cast iron items, including curved gutters to customer spec.

Their catalogue is a thing to behold - it's like stepping back to 1890, their range of rainwater and other goods is absolutely huge compared to the other, more modern manufacturers, if they don't make it then it's highly unlikely that you'll need it. Nice firm to deal with and quite reasnobly priced I found. They're not really on the internet (well, 1 brief page) - they belong to a bygone era!

As to how you'd fix a gutter and make it work - can't really tell from that picture, need some more close-ups.

 

[Moo]

Would the guttering have to be visible? We had a flat-roofed bay in our house-before-last, and it had a sort of gulley round the inner edge, leading to a discreetly positioned downpipe.

 

[Penners]

Joce - I'm not sure that a gutter is what you need. As there is no roof overhang, the gutter would need to be a watertight seal to the wall, all the way round that curved section of the building. Very difficult to achieve, I suggest.

I assume that the water you've seen flowing down the wall is run-off from the flat roof behind the battlements? If so, then I assume that the surface of the roof is not far below the lower sections of the crenellations. Is that right?

So what exactly is happening when it rains? If there is no existing rainwater discharge arrangement from the flat roof, is it becoming a lake, filling up as far as the lower parts of the crenellations and then overflowing through these gaps? If so, then I think you'd be better to consider creating a couple of holes through the parapet flush with the flat roof level, so the water can flow out of these. On the outside wall you can then fix hoppers immediately under the holes, with downpipes. You could even have a couple of gargoyles!

A photo of the roof arrangement behind the parapet would be useful, if you feel brave enough to venture up a ladder.

 

[Moo]

I think you'd be better to consider creating a couple of holes through the parapet flush with the flat roof level, so the water can flow out of these. On the outside wall you can then fix hoppers immediately under the holes, with downpipes. You could even have a couple of gargoyles!

Another nail hit squarely on the head by Mr P!

 

[Feltwell]

Needs more pictures I think!

Joce - I'm not sure that a gutter is what you need. As there is no roof overhang, the gutter would need to be a watertight seal to the wall, all the way round that curved section of the building. Very difficult to achieve, I suggest.

On further thought, I'd say you're right.

If so, then I think you'd be better to consider creating a couple of holes through the parapet flush with the flat roof level, so the water can flow out of these. On the outside wall you can then fix hoppers immediately under the holes, with downpipes.

Agreed, but not sure it's quite as simple as that. You'd need some kind of spout to throw the water clear of the wall, otherwise you'd have to seal the hoppers to the wall, which wouldn't last. Easy enough to form a spout with some lead sheet but it would need to tuck under whatever the flat roofing material is, jointed in such a way to prevent any water ingress. Easy to do when the roof is being built but maybe not so easy as a retro-fit.

Alternatively, if the roof is "ponding" at the moment and that isn't causing any issues, then a pipe drilled through to lower the water level but not bring it all the way down to roof level - like an overflow pipe - would be easy & cheap to do, and could still discharge into a hopper. Hoppers can be a bit of a pain though, they are very prone to getting blocked by leaves.

I'd still get Longbottom's catalogue, apart from anything else they do a huge range of hoppers.

People tend to get a bit obsessed by not having any "puddles" left on flat roofs, when actually a bit of standing water doesn't do any harm. A roofer I used a while back said that the reason fine gravel often gets spread on flat roofs wasn't really much to do with protecting the roof, it was more aesthetics so you couldn't see the puddles! He recommended not putting stones on - they tend to block downpipes if they come off the roof (exactly what happened here) and if the roof gets walked on they get pressed into the surface of the felt and can puncture it. Some reckon they are needed for UV protection for the felt, his opinion (bearing in mind he'd been fitting flat roofs for over 40 years) was that was nonsense and they did more harm than good.

 

[AMc]

People tend to get a bit obsessed by not having any "puddles" left on flat roofs, when actually a bit of standing water doesn't do any harm. A roofer I used a while back said that the reason fine gravel often gets spread on flat roofs wasn't really much to do with protecting the roof, it was more aesthetics so you couldn't see the puddles! He recommended not putting stones on - they tend to block downpipes if they come off the roof (exactly what happened here) and if the roof gets walked on they get pressed into the surface of the felt and can puncture it. Some reckon they are needed for UV protection for the felt, his opinion (bearing in mind he'd been fitting flat roofs for over 40 years) was that was nonsense and they did more harm than good.

A Grand Designs a long while back was focused on a 19th C house near our old London flat.
One of the things the German (IIRC ?) architect specified was a section of flat roof which had a permanent puddle to protect the roofing material from UV. IIRC it also had gravel. This being the "correct" way to do a flat roof and the way they did it in Germany (?) There was a lot of "I'm not sure it'll work" etc. from Kev and sure enough it leaked and forced them to take half the slate pitch above it to repair the problem.

Could have been this one
http://www.channel4.com/4homes/on-tv/grand-designs/episode-guides/hackney-the-terrace-conversion-08-05-15/display/image/hackney-roof-lg

My little porch roof is flat and puddles a bit - I cleaned all the moss out and saw no damage so now I don't care

 

[tobydog]

Call me mean :twisted: but that's the only Grand Designs I can recall where I actually wanted something to fail. I thought the owner and architect were really smug and the Rule Britannia in me came flooding out!! Sorry - I'm dragging this off topic.

 

[Feltwell]

I know what you mean, that architect was smug. However, no episode looked more doomed to failure at a very early stage than the chap trying to build a houseboat on an old barge from nothing but scrap with next to no skills - and as we saw on here a while ago, the barge ended up beached and abandoned somewhere near Brighton I think. I felt sorry for him, despite it being self-induced - he had a young family as well, and blew all his money on that boat.

 

[JoceAndChris]

Thank you so much for the thoughts on the flat roof and puddling problems. However that's not really the issue, sorry I wasn't very clear in my explanation. The roof's fine - a lead roof sloping ever so slightly so that water channels into the lead lined chestnut guttering, and various downpipes. It all takes a lot of clearing out of leaves as Feltwell says, but Chris is very good about doing that, as we desperately need our rainwater, and has bought a petrol leaf blower for the job! And we had all our rainwater drains cleared this year, and a new one constructed that I posted about. Some more pics of how it works:

In the middle of the picture is the gulley that both the lead and the slates drain their water onto.

This one from last winter shows the snow sitting on top of the lead, near the downpipe. It also shows the snow sitting on the front of the crenellations
- and that's the problem. Rain and snow slanting from the north will hit the building without ever landing on the roof and find its way into the gaps in the cement render. If only rain would fall vertically, but it doesn't always. All the rain that hits the battlements on the garden facing side just pours down; that's what I saw this morning.

I take the point that curving guttering would be very difficult and may not work. I suppose the thing is that you have to go back to breathable construction methods in lime and then it doesn't matter about this facade getting wet.

Thanks for the rainwater goods catalogue link Feltwell, I'll certainly get a copy, it sounds brilliant.

 

[Feltwell]

Not much you can do about driving rain hitting the face of a wall!

You already know that re-rendering in breathable materials is the way to go, but for now even if you just rake out and fill the cracks in your cement render it will help and it won't take long to do. Rake them out to an inverted V shape (so the base of the crack against the wall underneath the render is wider than it is at the surface) and fill with mortar, pressing it firmly into the V.

 

[worms]

Did we ever answer the question about the proper drip groove under the window ledges? It would be very easy for the later addition of the render to be bridging this.

Although if my geography on all this is correct, is the damp side, not the bit nearest the main body of the house? Looks to me like one of those incurable damp corners, but I accept that my perception is based on life in a much wetter climate!

 

[Penners]

Rain and snow slanting from the north will hit the building without ever landing on the roof and find its way into the gaps in the cement render. If only rain would fall vertically, but it doesn't always. All the rain that hits the battlements on the garden facing side just pours down; that's what I saw this morning.

In that case, As Feltwell has observed, there's not much you can do about the cascading water, other than ensure that the wall is properly able to cope with this.

It strikes me that, in this regard, you have two conflicting pressures to deal with. On the one hand, it could reasonably be argued that an intact cement render will be your best protection against driving rainwater (I emphasise "intact"). But on the other hand, once that water soaks into the ground at the foot of the wall, it risks wicking up into the masonry, in which case you need lime render to allow this damp to be given off. It's also the case, as you know, that the slightest fault in the cement render will allow moisture in, and prevent it from escaping.

Of course the long-term better plan is lime render. In the meantime, as Feltwell and worms have both said, you need to need to deal with every little fault that you can find in the cement render, and to do something about the windowsill that has no drip bar/groove. You'll obviously find it difficult to cut a groove, but I wonder whether there's any possibility of fitting a small bar underneath the front bottom edge of the sill, to induce dripping. You should also look very carefully at the seam where the bottom face of the sill enters the rendering, and make sure it's completely sealed.

Either that or do something to persuade the rain to fall vertically.

 

[Moo]

do something to persuade the rain to fall vertically.

- something like a great big awning* over the whole lot, and projecting several feet beyond the wall in question?



*You might be able to pick one up cheap from a wide-fronted shop that's closing down.

 

[Feltwell]

As your house isn't listed, you could always put something subtle like this up to protect it

http://www.geograph.org.uk/photo/2519330

 

[MdB]

As your house isn't listed, you could always put something subtle like this up to protect it

http://www.geograph.org.uk/photo/2519330

I would go with one of these. Just a little bit smarter..

 

[worms]

I wonder whether there's any possibility of fitting a small bar underneath the front bottom edge of the sill, to induce dripping...

A bead of sealant at the outer edge of the sill might do the trick - it worked for me once on a Land Rover, but the principle is the same!