Stone (sandstone?) Bay Roof Water Penetration ?

[Jumbo Jim]

I have a terrace house (dates from about 1910) with a bay front (see pic below) with solid 9" brick wall.

The bay wall in the upstairs bedroom is letting water in under the stone cill under each of the two bay window column areas. I initially thought this may be penetrating through the wall but I'm thinking could it possibly be penetrating down through the sandstone columns from the top ?

I briefly took a look at the top of the bay roof and there appears to be no felt or lead covering - is this normal ?

Also there was standing water in the stone gully which runs around the edge of the top of the bay roof - with hindsight (and now I've given the ladder back to the bloke I borrowed it off) I think the outflow pipe may be blocked. Hopefully if this is the case and I clear any blockage this will empty the gully.

However two questions;
a) is it realistic that could water penetrate the way I've described ?
b) should the bay have some sort of covering rather than bare stone eg lead, bitumen, felt ?

TIA - JJ

BayWindow

• Jumbo Jim
• 18 Nov 2019

 

[bobasd]

why not post pics showing the bay roof - the bay roof outlet pipe(is it clear?) - and the main roof gutter and fascia above the bay?
and pics of the inside damp stains?

 

[Jumbo Jim]

why not post pics showing the bay roof - the bay roof outlet pipe(is it clear?) - and the main roof gutter and fascia above the bay?
and pics of the inside damp stains?

Outflow is to right at top of bay (you can see it just jutting out in pic) but main damp is under left pillar just under cill. Minor patch of staining on inside ceiling same side as outflow. I will getter better photos when I get loan of ladders next weekend. I'm not at home when its light during the week. Its more the concept of whether this could be the problem and whether its usual for a bay to have no felt or lead cover ?

 

[bobasd]

yes, i had seen the outflow pipe but wanted to know if it was blocked or clear - and how it was attached to the stonework?
what material is the pipe?
that arrangement for water discharge is not good enough - thats why buildings have down pipes and discharge to gullies.
fwiw: sometimes water can enter at one place and show up at another location.

its not much use saying the roof should have this or that covering without seeing the roof, and knowing its dimensions.

 

[Jumbo Jim]

Managed to get back up today - the outflow pipe from the gully on top (right hand side) of the bay WAS blocked so cleared that out.
There is a gap in the join in the gutter (smack bang in the middle of the bay) that runs along the main roof so I expect water will escape from here particularly in heavy rain - although not sure if that will make any difference. If the bay roof is leaking then surely it will leak from rain landing on it as well as water escaping from the roof gutter.
Hopefully clearing the outflow will be a benefit. I'm still unsure as to whether I should get the bay covered with felt - there are a mix of properties with no felt or lead.
Fundamentally I suppose it can't hurt to cover the bay with felt other than it could be unnecessary cost.
There's a bit of standing water in the bay gully on the left which is on the opposite side of the outflow pipe - nothing I can do to shift this other than create another outflow on that side but that could create bigger problem by drilling etc so won't be doing that. Only thing is in heavy rain water may run over the side and down one side of bay.

Suppose it will be a case of monitoring to see if any improvement.

Opinions invited on whether felting the bay roof is advisable ?

Roof4

• Jumbo Jim
• 23 Nov 2019

Roof3

• Jumbo Jim
• 23 Nov 2019

Roof7

• Jumbo Jim
• 23 Nov 2019

Roof2

• Jumbo Jim
• 23 Nov 2019

 

[datarebal]

Fix the gutter clear off the moss, allow the roof to do as was designed

 

[Alastairreid]

Looks like asphalt, as data said, get the cast gutter sorted out, clean the bay off and give it a coat of acrypol or such like.

 

[bobasd]

1. clean out and re-make the gutter join, & secure your gutter to match the terrace falls.
2. some of the bottom course slate, and under slate need re-fixing.
there doesn't seem to be any underfelt below the slates?
3. the lead flashing needs removing (it seems its held in place by gravity) and properly re-fixed by chasing into a mortar bed.
this could be a tricky task unless the guttering above was removed.
4. moisture could be entering the roof at the join with the main elevation behind the flashing?
5. the roof surface literally needs scrubbing clean.
6. the outlet pipe needs water testing.
7. the thin smear of asphalt might be cracked, its already crazed - scrubbing will reveal any damage - but, as suggested above, coating the roof with Acrypol should give you a few more years.
8. when clean and primed, the L/H side of the gulley could be built up to to falls with some thick coat bitumen.

still waiting for pics of internal water damage?
how come no pics of the stone sills?

 

[Jumbo Jim]

still waiting for pics of internal water damage?
how come no pics of the stone sills?

This is the ceiling in the bay the same side as the outflow pipe.
I didn't bother with of photos of the sills as the mortar/brickwork/seals were all really good when I checked.
The only thing I can think is that water is possibly coming down the inside of roof and down the two pillars which caused some damage to plasterwork at floor level below each pillar.
I'm avoiding removing the pvc panelling and insulation covering the pillars at this stage and hoping by curing bay roof issue will fix that.

 

[bobasd]

if you dont show pics of all the interior water damage, and of the sills then its difficult to help you further.