Can 'weep holes' be drilled into the outer leaf of a cavity that is filled with Bead

ArdDonagh

There is a considerable amount of water on the inside of the outer leaf of the gable end of my new (1 year old) house which is facing west and driving wind and rain from the Atlanctic. This water does not appear to have breached the cavity except where it met the window in the hall and the DPC was installed incorrectly. The cavity is filled with Eco Bead. Wet damp patches stated to appear around the window in the hall and the builder reinstalled the window making sure that the DPC was inserted correctly (last week). As the window has not yet been sealed on the outside I noticed that water in running out through the top of the window where it meets the lintel and down the window panes and out both sides of the window where it meets the sill, and the footpath is soakin wet underneath. When the builder seals the window up the water will run into the cavity and onto the DPC layer and has nowhere to go. I have noticed for some months now that the footpath where it meets the gable end of the house on this side is always wet like water is trying to soak out. However it looks like water is soaking out much slower than it is building up inside. Would 'weep holes' serve any purpose. I belive that vents cannot be used as they would agitate the Eco bed causing air pockets.

RKQ

ArdDonagh wrote: »

There is a considerable amount of water on the inside of the outer leaf of the gable end of my new (1 year old) house which is facing west and driving wind and rain from the Atlanctic.

The cavity is filled with Eco Bead. Wet damp patches stated to appear around the window in the hall However it looks like water is soaking out much slower than it is building up inside. Would 'weep holes' serve any purpose. I belive that vents cannot be used as they would agitate the Eco bed causing air pockets.

Check with Eco bead or their IAB cert.
You believe that "vents cannot be used as they would agitate the Eco bead". This may be true but Eco bead is only polystyrene, so I'd risk it rather that risk having wet internal walls, damp etc.

Small brick vents at the bottom of the wall, over dpc level, should help to dry out the block or at least offer an escape route for water.

You have decided to fill the cavity, which IMO has made the cavity redundant. Your construction depends on good render, to remain dry. Maybe you should investigate ways to seal this gable elevation or add another coat of render. (always use breathable materials)

Maybe if the gable is painted, this will add to the sealing of the render and therefore the block work.

ArdDonagh

My house is part of an Estate of houses. However, mine is the highest up and the most exposed. These houses were sold as "super warm" and it was the builder who had the Eco Bead installed so I presume I would have to approach them for any further information. I am coming to the conclusion that the render used has no water repellant material in it. The house is painted. The reason I was advised against vents was because it is so windy here and there is the possibility of it causing air pockets in the bead and these air pockets would cause damp spots in the inside walls as they would be cold meeting the heat inside.

I am going to put your suggestion re "other ways of sealing the gable end" to the builder. Do you know if products such as AquaSeal (painted on) - I found it on a web search - or would re-rendering the wall be the better way to go?

Slig

If the DPCs were positioned correctly then the water should have no option but to pass through the outer leaf again at the bottom.

Is there any damp evident inside? If it aint broke dont fix it!
by adding holes you could actually allow another avenue for water to get in.

ArdDonagh

Slig wrote: »

If the DPCs were positioned correctly then the water should have no option but to pass through the outer leaf again at the bottom.

Is there any damp evident inside? If it aint broke dont fix it!
by adding holes you could actually allow another avenue for water to get in.

That is what I am afraid of - letting more water in! The only place where damp was evident was around the window, which they have taken out, fixed the DPC which was "in a ball" in the cavity and put the window back in. Does the water just come out through the outer leaf at floor level - is that how it is supposed to work?

Slig

ArdDonagh wrote: »

That is what I am afraid of - letting more water in! The only place where damp was evident was around the window, which they have taken out, fixed the DPC which was "in a ball" in the cavity and put the window back in. Does the water just come out through the outer leaf at floor level - is that how it is supposed to work?

To put it simply yes. That is the basis for the cavity wall system, the outer leaf is a "protection" wall. it is meant to take all the abuse from the weather in order to protect the inner leaf and the 2 should not be in contact.

Adding cavity fill insulation to "bridge" the two leafs has just fluffed the system. There are alot of people that dont agree with it(myself included) but it is certified by people greater than me so....

MacTheKnife1

Slig wrote: »

Adding cavity fill insulation to "bridge" the two leafs has just fluffed the system. There are alot of people that dont agree with it(myself included) but it is certified by people greater than me so....

Hang on - surely the problem is because of the messed up DPC in the window? Would not the exact same problem have occured if the OP had sheets of Kingspan installed??

Am not a builder but it does seem to me that eco beads can hardly be blamed for the stupid mistake with the DPC which is described above.

ArdDonagh

MacTheKnife1 wrote: »

Hang on - surely the problem is because of the messed up DPC in the window? Would not the exact same problem have occured if the OP had sheets of Kingspan installed??

Am not a builder but it does seem to me that eco beads can hardly be blamed for the stupid mistake with the DPC which is described above.

The damp around the window was definitely caused by the DPC not being fitted correctly. There was a yellow fluffy type insulation around the window which was saturated and has been taken out (I have been told that this type of insulation is put in around windows and doors to keep the EcoBead from escaping and getting into window/door frame.) Even though the outer leaf in soaking wet on the inside, the inner leaf is dry and the Eco Bead is completely dry also - even the bead that is up against the wet outer leaf.

MacTheKnife1

ArdDonagh wrote: »

Even though the outer leaf in soaking wet on the inside, the inner leaf is dry and the Eco Bead is completely dry also - even the bead that is up against the wet outer leaf.

OK thanks very much for this - it does seem to confirm that the EcoBead is working fine, no problems.

I have a spec ready to go to a builder which clearly states EcoBead as my insulation. I want to be sure this is the right path to go down.

Mac

Slig

MacTheKnife1 wrote: »

Hang on - surely the problem is because of the messed up DPC in the window? Would not the exact same problem have occured if the OP had sheets of Kingspan installed??

Am not a builder but it does seem to me that eco beads can hardly be blamed for the stupid mistake with the DPC which is described above.

Sorry for muddying the water. In this instance it is definately the DPC that is at fault.
In the bigger picture I dont see how a cavity wall is meant to work as a cavity wall if there is no cavity, but as I stated previously this is just my opinion. If you want to dispence with the cavity then surely there is no point in all the extra hassle of building it in the first place.

If you are building a cavity then 75mm of polyurethane will generally give you a much better U-value and still retain a cavity.

MacTheKnife1

Slig wrote: »

In the bigger picture I dont see how a cavity wall is meant to work as a cavity wall if there is no cavity, but as I stated previously this is just my opinion.

The cavity in the past contained air. Ecobead replaces the air with a bead. Neither the air nor the bead allows water to cross. To me the cavity is still a cavity, the medium contained within it now has a much better U Value than air. No other difference??

Slig wrote: »

If you are building a cavity then 75mm of polyurethane will generally give you a much better U-value and still retain a cavity.

I would love to go with PolyU but am very worried that the brickies will drop cement into cavity on top of boards, that board joins will not be up to scratch, that boards may be damaged whilst being installed etc etc etc. I cannot be there during the build so I am going for what I see is a safer option. Also cheaper -the brickies will charge less if they do not have to worry about insulation panels.

My paents house - built 1970 had the cavities pumped full of some sort of foam back in 1990 - there have been no issues with dampness wince then. Surely pumping full of foam or pumping full of eco bead is the same???

Sorry I am not a builder so the above may be incorrect in some way...

Slig

MacTheKnife1 wrote: »

The cavity in the past contained air. Ecobead replaces the air with a bead. Neither the air nor the bead allows water to cross. To me the cavity is still a cavity, the medium contained within it now has a much better U Value than air. No other difference??




I would love to go with PolyU but am very worried that the brickies will drop cement into cavity on top of boards, that board joins will not be up to scratch, that boards may be damaged whilst being installed etc etc etc. I cannot be there during the build so I am going for what I see is a safer option. Also cheaper -the brickies will charge less if they do not have to worry about insulation panels.

My paents house - built 1970 had the cavities pumped full of some sort of foam back in 1990 - there have been no issues with dampness wince then. Surely pumping full of foam or pumping full of eco bead is the same???

Sorry I am not a builder so the above may be incorrect in some way...

Your argument makes an awful lot of sence. I cant fault your reasoning at all. But just to clarify something you probably already know, you still have to make sure that mortar doesnt drop into the cavity as if it builds up on the tie then it can still cause damp. just as an option try looking into Aeroboard cavity fill boards.