Rendering below floor level?

[leiela]

Hi there,

We have an old Victorian house with a basement. As such the internal floor level of the main house is 4ft above the street level.

We have been getting quotes for rendering the building, some have suggested rendering to the floor while others say that you shouldn't render below the internal floor level and we should knock off the cement that's on the brick there and simply paint what's below.

It worries me that I'm getting such different advice which is correct?

 

[Monkey Boy]

Generally one would avoid rendering on a house bridging a damp proof course?
You may remember a program on TV called “rising damp” and never really heard that phrase much since then because houses have damp proof courses (slate years ago, plastic now and recent decades) to stop the building soaking moisture up from the ground like a straw. Our grandfathers would have heard of that phrase way more than we ever did. If you render over it than you have reintroduced the straw like effect allowing moisture to pass up and above the dpc Mrs Jones
Your basement will have its own unique placement (if any) of dpc and could be anywhere or non existent so the floor level of your house may be irrelevant on the decision of where to render or not

 

[leiela]

yeah i was reading about DPC but i can't figure out for the life of me if we have one haha .... i suspect we dont, but there is a layer of the house that's 'different' to the rest ..

The top portion of the house is solid brick (double bricks) but the basement and this 4ft band around the base of the house appears (looking at it from inside the basement) to be sandstone which seems like an odd DPC if that is what it's supposed to be... but then again what do i know im not in any way shape of form a builder or renderer...hence asking the questions.

 

[raytheplasterer]

solid brick victorian houses generally don't have damp proof courses.

 

[leiela]

solid brick victorian houses generally don't have damp proof courses.

Does that mean we can/should render to ground level?

 

[raytheplasterer]

You'd really need to get a competent plasterer/renderer out to look at it, someone who has a good reputation and experience to look at it in person, if the mortar in the bricks is lime and the bricks are quite soft, you'd have to get it done in lime. Depends what part of the Victorian era it is.

 

[leiela]

You'd really need to get a competent plasterer/renderer out to look at it, someone who has a good reputation and experience to look at it in person, if the mortar in the bricks is lime and the bricks are quite soft, you'd have to get it done in lime. Depends what part of the Victorian era it is.

we've been trying but we keep getting different opinions and we can't seem to find some solid advice we can rely on we arn't builders so we are relying on getting people in. Every rendering company we speak to seems to have a different opinion and each insist they know best.

Honestly at this point i'm really overwhelmed, how is anyone supposed to get things done correctly when working out what the correct thing is when no-one seems to agree what that is. The house was build in 1860 and currently has badly blown concrete render that we think was done in the 50-60's.

 

[raytheplasterer]

You should get your concrete render very carefully and slowly removed so as not to damage your brickwork
and go from there, an 1860 house should never have cement render on it.
It's possible that the house would have been tanked as it has a basement and is so old, so might have also been tanked up to waist level on the ground floor, It's possible to render the outside in lime to the floor in this situation as long as there is a concrete pathway around the house and you won't be putting any earth or flowerbeds against the wall of the house. You could render to the floor even if it hasn't been already tanked, but could possibly cause a damp issue in the future.

You are probably best off carefully removing the area of render on the house and repairing the mortar and leaving it bare brick. But removing the cement render could destroy your brickwork so you would have to get it rendered in lime.

 

[leiela]

You should get your concrete render very carefully and slowly removed so as not to damage your brickwork
and go from there, an 1860 house should never have cement render on it.
It's possible that the house would have been tanked as it has a basement and is so old, so might have also been tanked up to waist level on the ground floor, It's possible to render the outside in lime to the floor in this situation as long as there is a concrete pathway around the house and you won't be putting any earth or flowerbeds against the wall of the house. You could render to the floor even if it hasn't been already tanked, but could possibly cause a damp issue in the future.

You are probably best off carefully removing the area of render on the house and repairing the mortar and leaving it bare brick. But removing the cement render could destroy your brickwork so you would have to get it rendered in lime.

we don't think the basement has ever been tanked, the walls are bare blocks for the most part and they dont appear to have any coating on them there is concrete all around the house so no issues of earth or flowerbeds.

 

[raytheplasterer]

whoever will do your work and if they render to the floor in lime render will build an extra thickness at the bottom of the wall that meets the floor, it's called a "plinth" , it's from 1 to 2 foot from the ground and will have a slope at the top to help water run off, that should help to stop the water causing damp issues in the house.

 

[leiela]

whoever will do your work and if they render to the floor in lime render will build an extra thickness at the bottom of the wall that meets the floor, it's called a "plinth" , it's from 1 to 2 foot from the ground and will have a slope at the top to help water run off, that should help to stop the water causing damp issues in the house.

ooh that sounds like what we have already, ok so i have a name for it now, but i'm pretty sure it's not currently Lime.

 

[Monkey Boy]

The house was build in 1860 and currently has badly blown concrete render that we think was done in the 50-60's.

Stick some pictures up
Not that it will generate any extra advice than have already received but may throw a new direction on thought

 

[leiela]

here we go

 

[leiela]

it looks like the grass goes up to the building, but there is a small gap with concrete and we are getting rid of those beds anyway very shortly. The whole gable end is concreted at the base/floor as it's the driveway.

 

[Bella83]

Hi Leiela,
Whereabouts are you? Your house will have been built in lime and it's quite possible, given the age, that it's been rendered either in cement or a lime and cement hybrid, which was quite common in the late 1800s. If it is, it is often a lot harder than cement and can take a lot of work to get off.

A French drain will help out around the house, and will help divert water away from the foundations and the basement. If you're anywhere along the M4/ Wales/ South West, I might be able to have a look for you.

Bel

 

[leiela]

we are up in liverpool so not too close i'm afraid. we had someone perform a heritage survay on the house he said the current render was cement. He said other than the rubbish render the house was actually coping with damp quite well and that simply removing the cement would fix the issues we have.

Sadly struggling to figure out what to put on the walls instead everyone seems to have a different opinion of what and how. Next door hans't got render just painted bricks but they have issues as well which we think is a similar issue of the paint trapping the water in the bricks.

 

[Ktownsend]

we are up in liverpool so not too close i'm afraid. we had someone perform a heritage survay on the house he said the current render was cement. He said other than the rubbish render the house was actually coping with damp quite well and that simply removing the cement would fix the issues we have.

Sadly struggling to figure out what to put on the walls instead everyone seems to have a different opinion of what and how. Next door hans't got render just painted bricks but they have issues as well which we think is a similar issue of the paint trapping the water in the bricks.

Use lime wash and painting the bricks will be fine

 

[FreeD]

Hi Leiela,
Whereabouts are you? Your house will have been built in lime and it's quite possible, given the age, that it's been rendered either in cement or a lime and cement hybrid, which was quite common in the late 1800s. If it is, it is often a lot harder than cement and can take a lot of work to get off.

A French drain will help out around the house, and will help divert water away from the foundations and the basement. If you're anywhere along the M4/ Wales/ South West, I might be able to have a look for you.

Bel

Not sure french drain against the house is good advice they can easily become blocked and cause further issues and are rarely installed well.

We usually use a lime render at damp proof course level (no cement) if it's sandstone maybe a bath stone premix?

Depending on the subsoil you could dig a trench near to the house and fill with pea gravel.

If in doubt always use a breathable lime render (no cement)

 

[Smooth criminal]

100% lime this property would be a really nice one to do..
Is there any visible air vents around the building youd be very surprised how many people render over them creating poor ventilation... Especially if you have solid sub floors s@c floors that building will sweat...

 

[Bella83]

Not sure french drain against the house is good advice they can easily become blocked and cause further issues and are rarely installed well.

We usually use a lime render at damp proof course level (no cement) if it's sandstone maybe a bath stone premix?

Depending on the subsoil you could dig a trench near to the house and fill with pea gravel.

If in doubt always use a breathable lime render (no cement)

It's standard practice here to do that. We always do French drain at base of wall, well lined, decent aggregate and a pipe. You could say that (things are often not done well) about anything in construction.. the idea when suggesting them (or at least the hope!) is that they will be done correctly and by someone competent. Removing as much concrete around floor level, particularly if the outside is any higher than internal is always a good start. We're in a very high rainfall / exposure area so everything is always pretty much a belt and braces approach- harled render, french drains, bellcasts and plinths to try and shed as much rain as possible.

 

[The Hobo]

we are up in liverpool so not too close i'm afraid. we had someone perform a heritage survay on the house he said the current render was cement. He said other than the rubbish render the house was actually coping with damp quite well and that simply removing the cement would fix the issues we have.

Sadly struggling to figure out what to put on the walls instead everyone seems to have a different opinion of what and how. Next door hans't got render just painted bricks but they have issues as well which we think is a similar issue of the paint trapping the water in the bricks.

take the render off for sure no good on a house that age

 

[FreeD]

It's standard practice here to do that. We always do French drain at base of wall, well lined, decent aggregate and a pipe. You could say that (things are often not done well) about anything in construction.. the idea when suggesting them (or at least the hope!) is that they will be done correctly and by someone competent. Removing as much concrete around floor level, particularly if the outside is any higher than internal is always a good start. We're in a very high rainfall / exposure area so everything is always pretty much a belt and braces approach- harled render, french drains, bellcasts and plinths to try and shed as much rain as possible.

Fair enough...it's the ACO drains I don't like.