Can rain water penetrate my external walls?

[aldo123]

I have a new (ca 9 month old) house from a reputable builder. The house is white rough cast/pebble dash or whatever it is called - scratch coat went on, white cement type base layer and then little white stones were thrown at the render to create the finish.

I've recently started to get water in my lounge from the bay window roof area and the builder has come out and replaced the lead flashing but it still gets in usually when it is wet and windy together. On closer inspection it appears to be water coming from the cavity as they removed the plaster board on the ceiling and you could see the bottom of the lintel was wet as water is being stopped by the damp proof course and pushed to the outside edge of the lintel where it seeps through the mortar bed.

They then used a scope to try and understand why water was getting through the cavity tray above the DPC and found a crack in the plastic. They have proposed to come next week and remove a few bricks to repair that and in the mean time sealed up the weep vents as that was where the water was coming from due to the wind driving rain in the vents.

Last night, with my weep vents completely sealed we had yet more water get in to the lounge (not a lot though). Is there any other way that water can enter the cavity in my house? I assume if the cavity tray is there it has a purpose! Will my rough casting not make the brickwork completely water proof or could water still get driven in by rain and wind?

Any advice appreciated.

 

[roy c]

Obviously someone has cocked up some where, Dashed render is used in high risk areas where there is a lot of wind and rain and exposed areas. The dash stops the rain from running down in straight lines (like it does on flat render.) But it shouldn't be coming thru to the inside walls! Therefore I reckon that the cavity tray might have been damaged when built or the flashings are not doing the job. Get some pictures up of the outside and inside where the water is coming in.. Is the bay roof fibre glassed or felted?

 

[^woody^]

Weep vents should not be sealed up, as then moisture exits somewhere else.

Rendered walls should not be getting a great deal of moisture through it in any case, so the area right up to the roof eaves should be checked. Cills, cill drips and window reveals particularly.

 

[freddiemercurystwin]

Therefore I reckon that the cavity tray might have been damaged when built

Assuming there is one .......