# damp walls



## weatherwatcher

Hi everyone
we finally arrived here in central Portugal and work has started on our house, our builder has shown us we have a problem with water coming through on the outside wall, the one that the weather hits all the time. He tells us that the problem can be cured but waterproof paint (1) is this correct (2) what sort of price . Our house is a square "box" and measures approx. 6metres x 7 metres 2 storeys high. The builder tells us he can do the job for 2,500 euros which sounds a lot to us. Can anyone advise please


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## canoeman

Normal exterior paint used is "plastic" so does provide a waterproof element, not cheap here but wouldn't have thought 2500€.
What is current external finish? What exactly is your house construction? norm is concrete frame, twin wall with insulation between so you shouldn't get rain through a double skin, *my feeling is you should be getting a second opinion* before allowing him to proceed.

At this money if property is uninsulated I'd be looking at one of the external thermal cladding options that would give you insulation and a coloured finish of your choice that never needs painting again


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## BodgieMcBodge

You need to know what your place is constructed of and if it was designed to have one wall with a moisture barrier. If you have an exterior wall treated you run a serious risk of trapping damp within the wall by preventing it from evaporating, long term this will cause damage to the structure and rot in any wood work (floor or roof joist) which are wall supported. Do you know why there is water coming through the wall where presumably there was none before?


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## DREAMWEAVER1

Although exterior paint is expensive in Portugal,that sounds like a lot euros to me,considering the wall in question is only 42 S /metres,get a second quote,some Portuguese "builders" seem to be of the opinion that if you are British,you are fair game to be overcharged with an inflated quotation,if you question your "builders" quote,I bet he is able to find a reduction somewhere!

Good luck anyway!




David


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## maidentales

Our property is 118 sqm top and 60 sqm basement and detached. We were quoted around 2,000 Euros for fully painting the outside of the property in the elastic waterproofing exterior paint.

We pay 130 Euros for a 15 liter tin which covers an area of 10 x 7 meters of wall. We estimate that 6 pots of 15 litre paint tins would paint the entire house twice as the second coat uses less paint that the first.

6 x 130 Euros = 780 Euros for the paint and it's a largish not box like house.

My opinion that this a high price if he's quoting 1,720 labour costs or more.

This would waterproof the walls but I think you can also buy some black bitchamin although where you would get this from in Portugal I don't know, to coat the inside of the wall and this stops the damp coming through to the inside.

What we're doing is putting down silver damp proof membrain to allow the water to run under this in channels as it's not wise to let the water build up behind concrete or bricked up walls - it needs to go it's natural course ideally but flow behind brick walls into channels rather than being stopped totally.

The damp proof membrain should stop the water coming up the floor with rising damp problems

I would definitely go for a second quote and even a third quote as Portuguese builders can be quite notorious! I also suggest you don't pay upfront for materials as friends of ours did this and they haven't seen their materials nor their funds again even though the builder lives in a nearby village.

Best, if any doubt, to source and find your own and present it to however is doing the work - although that's just my opinion and may not be that of others.


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## weatherwatcher

canoeman said:


> Normal exterior paint used is "plastic" so does provide a waterproof element, not cheap here but wouldn't have thought 2500€.
> What is current external finish? What exactly is your house construction? norm is concrete frame, twin wall with insulation between so you shouldn't get rain through a double skin, *my feeling is you should be getting a second opinion* before allowing him to proceed.
> 
> At this money if property is uninsulated I'd be looking at one of the external thermal cladding options that would give you insulation and a coloured finish of your choice that never needs painting again


The house was built 1969 and it's brick but with a finish that looks like cement with lots of bits of green glass in it, In Spain they would call this finish gotogran but not sure what they call it here


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## canoeman

There are as many products as UK for damp proofing but unless you really know cause you're just taking cosmetic solutions, think weatherwatcher needs to find out where and how water/damp is entering house and how his " builder has shown us we have a problem with water coming through on the outside wall" might be faulty tiles, flashing or guttering, I'd certainly get a second opinion and understand how the house is constructed as unlikely to be driven rain on a double skinned building.

Build 1969 it should be a concrete framework with Tujla brick infill, might have twin walls might not, unlikely to be insulated between walls if double, sounds like a standard cement render has it hasn't been painted? could be slightly porous.

As I said if there is no internal insulation to walls then I would look at one of the exterior insulation options as a long term solution rather than just paint the walls, depending on how handy you are perfectly feasible to do initial cladding but have a builder do the mesh reinforcement and skim coats


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## weatherwatcher

weatherwatcher said:


> The house was built 1969 and it's brick but with a finish that looks like cement with lots of bits of green glass in it, In Spain they would call this finish gotogran but not sure what they call it here


 can you give us an idea of costs Canoeman for the thermal cladding you talk about, we did think the price quoted was a bit excessive. Thanks everyone for all replies.


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## canoeman

It's called cappoto here, think around 29€ m2 quite a number of companies supply systems, this is Robbialacs Viero | Sistema Cappotto | ETICS or this one shows how to do it.
http://www.lena.pt/images/uploads/ETICS Clientes.pdf


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## Centralbound

maidentales said:


> you can also buy some black bitchamin although where you would get this from in Portugal I don't know, to coat the inside of the wall and this stops the damp coming through to the inside.


Really, I despair. It's called bitumen in English; betume in Portuguese, sometimes (varios things) betuminoso, not to be confused with window putty which is sometimes also labelled betume. Most bricolages will have bitumen as solid cylinders that are melted and mopped, and some will have plasticised versions used at normal temperatures. It should never, ever be used in the way you suggest for a variety of reasons. If you don't know what you are talking about, and in this case you clearly do not, don't post and confuse matters.

Weatherman: do you know how the damp wall is constructed?


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## DREAMWEAVER1

Also known as bitumin,a thick viscous tar product used to coat a substrate in order to provide a level of protection.









David


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## canoeman

weatherwatcher appreciate system is expensive but partial DIY quite easy, but if you have one side that gets all the prevailing weather it's possible just to do that side or the two that take brunt


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## maidentales

I'm not a builder so technical terms illude me although I didn't realise that I would be pulled up for not getting the term exactly right.

We used bitumen (a black, sticky tar like substance that you paint on) in a property in Crete against the back of a wall which was locked into the hillside and that was used on the advice of a local builder in Crete, so my only digression was to not state it correctly in the name.

Sorry, but we did use this black tar on the wall to stop the damp coming through and it worked very well by draining the water through a channel and rendering over the top of the black tar and then painting it.

I put it on the wall myself so yes, it can be used in this way and I can provide photos if necessary to show that as evidence that it can be used in this way.

Apologies for not using the correct term and for correcting this on my behalf but I DO clearly know what I'm talking about even if I get the name wrong.

Therefore, please don't advise me not to post as I only post on things I am aware of or have experienced for myself - but good advice from you that I should check my spelling and/or make sure I get the technical terms correct instead which would be more useful to the member concerned as confirmed by follow ups by other members who have corrected my terms so thank you for this correction.

Sorry, I'm not perfect!


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## maidentales

Voila:

nikiaug07001.jpg Photo by maidentales | Photobucket

After:

http://s1101.photobucket.com/user/m... in the making/Mandys011.jpg.html?sort=3&o=11

I can only go on the advice of builders else why would I post as I'm not a builder.

However, best that the Member solves the reason behind the damp, such as leaking through the window etc., before deciding on action to be taken.


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## BodgieMcBodge

*No no no no no no don't do this* This would be akin to an overcoat with the waterproof layer on the inside.





maidentales said:


> Our property is 118 sqm top and 60 sqm basement and detached. We were quoted around 2,000 Euros for fully painting the outside of the property in the elastic waterproofing exterior paint.
> 
> We pay 130 Euros for a 15 liter tin which covers an area of 10 x 7 meters of wall. We estimate that 6 pots of 15 litre paint tins would paint the entire house twice as the second coat uses less paint that the first.
> 
> 6 x 130 Euros = 780 Euros for the paint and it's a largish not box like house.
> 
> My opinion that this a high price if he's quoting 1,720 labour costs or more.
> 
> This would waterproof the walls but I think *you can also buy some black bitchamin although where you would get this from in Portugal I don't know, to coat the inside of the wall *and this stops the damp coming through to the inside.
> 
> What we're doing is putting down silver damp proof membrain to allow the water to run under this in channels as it's not wise to let the water build up behind concrete or bricked up walls - it needs to go it's natural course ideally but flow behind brick walls into channels rather than being stopped totally.
> 
> The damp proof membrain should stop the water coming up the floor with rising damp problems
> 
> I would definitely go for a second quote and even a third quote as Portuguese builders can be quite notorious! I also suggest you don't pay upfront for materials as friends of ours did this and they haven't seen their materials nor their funds again even though the builder lives in a nearby village.
> 
> Best, if any doubt, to source and find your own and present it to however is doing the work - although that's just my opinion and may not be that of others.


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## maidentales

Other things to consider that we had to do on our property in Portugal, having learned a lot from the property in Crete which had similar problems:

Guttering - until we put full guttering around the Portuguese house, damp would seep into the stone much quicker and this has solved a lot of difficulties with damp walls.

Single hollow brick construction: No amount of weather proofing will stop water seeping through hollow bricks - and we have all of that in places where we have single hollow brick constructions and the rain lashes against the external wall.

To solve it we will be "battening out" internally, putting a damp proof lining behind the battoning, insulation as well and putting an inner skin to the affected area, either in wood or brick which we haven't decided on yet.

External soil level. If the external soil level is above the internal level of a floor, then water may seep through either stone or hollow bricks and splashing will create a higher level of damp up the wall.

To solve this with our property in Portugal, I dug down to below the floor height (in some places this was 5 ft deep x 10 ft x 10ft wide so it can mean a lot of work - all the way around the property. Concreting or paving could also help keep out the water.

Tree roots. These can bring water into the property and there's again not much that can be done if you want to keep the tree or it's a neighbour's, except to allow the water to take it's own course, drain it through channels and put together a waterproof barrier.

Again, if there's any question on the posting, these are all things that are currently taking place at our property and things that we are receiving professional advice on, mainly through UK professional builders who are friends.

We also stone paved the entire driveway the lenghth of the house and next to the house as we couldn't get the external soil below internal floor level, put in plenty of drainage channels and concreted and paved a flower bed next to the house, all of which has helped to solve damp walls without retaining the water within them by leaving drainage channels in the basement for the water to run through and out the other side.

Broken or ill fitting roof tiles. Cracked tiles around the edge of the roof (i.e., immediately above the stone or brick wall) could allow water to seep through the wall. Our old Portuguese property uses tin instead of lead for flashing which doesn't work well in very heavy rains, considering obtaining lead flashing if there are any chimneys to work with although it's an expensive option.

Our 100 year old Portuguese property uses concreting to secure the roof areas where the turns and edges of the roof are (again, I'm not a builder and don't know the terms), and this can lead to water dripping into the roof area into the house and down the stone or brick built walls.

If it's just splashing onto the external wall, it would be difficult to get through these old Portuguese 1m plus stone walls so it could be on your window recess which isn't so deep, where the damp is coming through: we have this issue and that's down to ill fitting windows rather than the wall itself.

I did renovate a stone ruin in Crete but no, I'm not a builder! I'm a labourer going on the advice of a professional UK builder and professional Crete builders which, as the property was built in stone and the property in Portugal is also built in stone, means that the principals remains the same and products remain the same throughought Europe, I suspect, if it solves a damp wall.

Hope you get it sorted and find the right solution although it could be possible to look into the cause and treat the cause rather than the symptom.


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## johnjohn47

Older building made of stone inevitably use whatever stone was available locally from fields or quarries eg Portland stone in Portland. The stone used in different parts of Portugal are different, just as say the stone in Crete is different to that in Portugal. The porosity of stone varies, that is the ability of moisture to wick through the stone. The stone house near Coimbra was made of stone which was impervious to water ie if you stand a stone in a bowl of water with a piece of tissue paper on top the paper never gets damp. How you treat a stone wall in one area is not necessary the same as the treatment in a different area because the stone is different. Generally walls have to breathe with the prevailing humidity; impervious stone relies on the pointing mortar to be permeable by using a high lime content. Covering such walls with an impervious layer is liable to cause long term damage to the wall by preventing any internal moisture from escaping. You do not have to be a builder to understand this.


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## weatherwatcher

It's constructed of the type of bricks used her in Europe which are like honeycombe and then there is the top coat/ render of what looks like cement/ concrete with lots of bits of green glass in it which looks like it's been blasted on. Our builder has shown us where there are some slight cracks in the outside render which is where the rain has been getting in , according to him.


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## canoeman

Sorry but I'd disagree with your builder to a degree, there's often some crazing to external rendering which might or might not reguire opening to fill, but it's very unlikely that it is sufficiently bad for water or the signs of water to appear inside which is my understanding from your original post.
If crazing was bad then it's best to open and fill but the external paint used here generally has sufficient elasticity to bridge minor cracks and also makes a waterproof seal to render.

If it's only a single skin "honeycomb" brick it might penetrate all the way through but unlikely, my guess would be that any internal damp is more likely to be condensation because of a single skin or a double skin with no insulation which is likely on a 69 build or condensation where the concrete beam structure of the house supplies a dense cold surface which again causes condensation internally, it's one of the reasons for applying external insulation in this sort of situation.

It could be that painting exterior will be your cheapest option to weatherproof walls but I'd want to know exactly what he will do to justify 2500€ which seems excessive, I'd also check, any flashing, guttering, roof and eaves


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## anapedrosa

Our house foundation is well protected as it is a recent build, but with this winter's rain we realized that we would need to remove the water from the property rather than let it sit and to reduce some of the soil erosion that is occurring due to the water streaming down the hill. 

I think paint would be a very temporary solution and may end up costing more than you anticipate in the redoing later. Have you considered draining the water away from the house - in Canada we would refer to this as weeping tiles.

On our property, we are looking at drains connected to the rain water sewers. They will dig a trench, place the tube (tubes are plastic with holes in them) and then fill the trench with gravel. 

In terms of quotes, we got one from the original builder, which we thought too high. Since we wanted some garden work done, we decided to bundle the work with some garden work. The garden centre quote was about a third of the builders. To be fair, the digging is a large part of the work. I mention this because 2500 was the builder quote for the drains, so there may be other options.

Be careful for price fixing as well. Builders in a small community will sometimes not bid against each other.


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## weatherwatcher

anapedrosa said:


> Our house foundation is well protected as it is a recent build, but with this winter's rain we realized that we would need to remove the water from the property rather than let it sit and to reduce some of the soil erosion that is occurring due to the water streaming down the hill.
> 
> I think paint would be a very temporary solution and may end up costing more than you anticipate in the redoing later. Have you considered draining the water away from the house - in Canada we would refer to this as weeping tiles.
> 
> On our property, we are looking at drains connected to the rain water sewers. They will dig a trench, place the tube (tubes are plastic with holes in them) and then fill the trench with gravel.
> 
> In terms of quotes, we got one from the original builder, which we thought too high. Since we wanted some garden work done, we decided to bundle the work with some garden work. The garden centre quote was about a third of the builders. To be fair, the digging is a large part of the work. I mention this because 2500 was the builder quote for the drains, so there may be other options.
> 
> Be careful for price fixing as well. Builders in a small community will sometimes not bid against each other.


Thanks for all replies. The damp is high up the walls not low down, around window height and above but not can I add around the windows so not coming from the windows


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## canoeman

Generally if high up it is condensation, treat with a mould killer and try dehumidifier


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## siobhanwf

Go for a decent dehumidifier. You will be surprised at how much liquid they suck. In Hong Kong they were a necessary part of living and we used them here without even thinking about it!


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## DREAMWEAVER1

siobhanwf said:


> Go for a decent dehumidifier. You will be surprised at how much liquid they suck. In Hong Kong they were a necessary part of living and we used them here without even thinking about it!


Our bedroom is suffering quite badly with both damp and mould on timber furniture,not having used a dehumidifier before,how often do you have them in use?

Obviously it depends on the severity of the damp,but once under control,how frequently do they have to be used to maintain a dry room,in your experience just to give me a rough idea of usage.

Many thanks

David


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## siobhanwf

In an unused room we would use at least for a couple of h ours every day. Or even leave running overnight in each room alternating.

If we go away we leAve one running constantly in each bathroom with all doors in side open....they drain into bath or shower.


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## canoeman

If you supply fresh ventilation less often, most decent dehumidifiers have controls to set frequency etc, important thing is to match dehumidifier to room size, more efficient, and treat mould first most supermarkets, builders merchant will sell spray product


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## DREAMWEAVER1

SB and CM,

Thanks both for your replies,most helpful,I have ordered an Ebac dehumidifier,a make I know and trust.

Thanks again both



David


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## siobhanwf

Do please let us know how you get on David


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## Bugwap

Hiya

I must admit that things improved for us when I took a big kango & installed some air bricks to ventilate our house.

Lets the air circulate & generally got rid of the problem.

Low tech can work


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## DREAMWEAVER1

Bugwap said:


> Hiya
> 
> I must admit that things improved for us when I took a big kango & installed some air bricks to ventilate our house.
> 
> Lets the air circulate & generally got rid of the problem.
> 
> Low tech can work


Hi Bugwap,

Our walls are 36 inches,or 900mm's thick,so air bricks aren't really an option,and we have aluminium vents in the base panel of 4 of our 6 exterior doors to assist with air movement,the house,a Presbytery built in 1880 obviously doesn't have a damp course,but all things considered it could be a lot worse,we are looking forward to the summer to dry everything out!

David


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## canoeman

Building regs in Portugal don't allow for a damp proof course, whatever there is is to supply external vertical damp proof below ground level.


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## DREAMWEAVER1

siobhanwf said:


> Do please let us know how you get on David


SB,

In reply to your request,we received an a English make of dehumidifier,Ebac on Monday,fitted the castors,plugged it in and set up in the master bedroom,within 4 hours the tank was at 1ltr,the humidity level was at 75%,after 26 hours the level has reduced to 71%,I am more than pleased with the results,just wish I had invested sooner!but better late than never!central Portugal very wet this year,I would suggest those with stone built houses,a dehumidifier is probably a must have!


David


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## siobhanwf

Glad it has worked for you Dave 

We have now had 5 reverse cycle air conditioning units fitted. These heat, cool and dehumidifier and are surprisingly cheap to run 

We have held on to 2 of our original dehumidifier.


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## DREAMWEAVER1

When we viewed our house last year,it was in July,I recall 30 degree's,however due to the metre thick walls of the old Presbytery,it was quite cool and refreshing,so it is this that I am relying on in not having to consider air conditioning,but I am not counting my chickens before they hatch,either way I am looking forward with great anticipation to the hot weather.






David


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## canoeman

Yes but you might need to still run dehumidifiers it doesn't go away because it's 30 degree's outside just feels like it


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## travelling-man

David

Can I ask where you bought the unit & how big it is etc please?


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## DREAMWEAVER1

travelling-man said:


> David
> 
> Can I ask where you bought the unit & how big it is etc please?


TM,

I brought the machine from English company, Ebac Direct,on line,a 2850E,removes 21 litres per 24 hours,from their 2000 Series,free 2 year full guarantee(if it breaks down during the 2 years,they collect,repair and return to Portugal FOC,this can be extended by 5 years for £45,giving 7 years guarantee).

5 day delivery,also impressive,a good machine,and so far wouldn't hesitate to recommend it,if you need a machine with this capability,go for it!

Good luck,

David


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## travelling-man

Thanks David.


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## siobhanwf

Was delivery included Dave or was it extra?


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## DREAMWEAVER1

siobhanwf said:


> Was delivery included Dave or was it extra?


The cost of delivery to mainland Portugal is £25.21 for the purchase of a 2850E machine,not unreasonable,I thought.




David


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## travelling-man

Might be worth looking on Amazon to see what deals and/or free delivery is available.

David

Is it a mains power unit?


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## DREAMWEAVER1

Yes TM,mains power,if you are looking of an Ebac machine,they charge extra for castors and perm drainage kit,I did check out Amazon,but you don't get the same guarantee period of 2 years,so checkout with care for like for like when making any choices,I did.







David


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## DREAMWEAVER1

SB,

Humidity down to 49% to complete 1st floor area!very impressed with Ebac,one of my better purchases!






David


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## siobhanwf

DREAMWEAVER1 said:


> SB,
> 
> Humidity down to 49% to complete 1st floor area!very impressed with Ebac,one of my better purchases!
> 
> 
> 
> 
> 
> 
> David


Thanks for the update David. They really do make a difference


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