How high should a stop bead be above a DPC?

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superspread said:
you could stick a stop bead below the dpc line,then just above this you stick a bell mouth bead leaving a 10mm gap so as not to bridge the dpc ,unless u get on your hands and Knees u would never see the gap cos the bell bead is masking it (this is of course if you want to render down to the ground)
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I use a bell cast bead for aesthetic reasons. People 'worry' about dampness 'rising ' in the render/bricks below the DPC to above the DPC with a 'bridged' DPC. Can anyone tell me why they are not worried about 'falling' damp (rain) which occurs above the DPC. Surely this would cause the same symtoms that 'rising' lol damp causes ????
Im not going to get dragged into another sticky on this one. A bit of common sense is required here :RpS_unsure:
 
irish_spread said:
I use a bell cast bead for aesthetic reasons. People 'worry' about dampness 'rising ' in the render/bricks below the DPC to above the DPC with a 'bridged' DPC. Can anyone tell me why they are not worried about 'falling' damp (rain) which occurs above the DPC. Surely this would cause the same symtoms that 'rising' lol damp causes ????
Im not going to get dragged into another sticky on this one. A bit of common sense is required here :RpS_unsure:
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Totally agree Irish ,I just cover all bases rather than any future comebacks
 
irish_spread said:
I use a bell cast bead for aesthetic reasons. People 'worry' about dampness 'rising ' in the render/bricks below the DPC to above the DPC with a 'bridged' DPC. Can anyone tell me why they are not worried about 'falling' damp (rain) which occurs above the DPC. Surely this would cause the same symtoms that 'rising' lol damp causes ????
Im not going to get dragged into another sticky on this one. A bit of common sense is required here :RpS_unsure:
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We do it because every surveyor in the land ,will look for it
 
keithuk said:
We do it because every surveyor in the land ,will look for it
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So,so true Keith. The problem with the damp industry (because that is what it is, an industry) is that surveyors and reps etc, read a book stating that damp will rise in render and bridge a dpc but cannot see the blindingly obvious fact that rain is erm, made out of water.
When a customer asks me for a chemical dpc, I always tell them it's a waste of money and tell them what is causing their particular damp problems. If they insist on a chem dpc I think, fook it and give them a MASSIVE price and generally still get the job :RpS_biggrin:
 
Funny enough, doing one now. Previously been injected and new plinth put in, damp again. Cause of damp ? Penetrating, funny enough :RpS_scared:
 
I don,t get involved with that anymore ,don,t want someone ringing me up in 10 years saying the damp you treated is back :RpS_scared:
 
superspread said:
you could stick a stop bead below the dpc line,then just above this you stick a bell mouth bead leaving a 10mm gap so as not to bridge the dpc ,unless u get on your hands and Knees u would never see the gap cos the bell bead is masking it (this is of course if you want to render down to the ground)
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Same as back to back stops, some insist on the flat and the design forgets to incorporate bricks under the dpc line, one job I'm going to tomorrow have to put brick slips over the blocks as the neighbour won't allow render plinth on their side
 
irish_spread said:
I use a bell cast bead for aesthetic reasons. People 'worry' about dampness 'rising ' in the render/bricks below the DPC to above the DPC with a 'bridged' DPC. Can anyone tell me why they are not worried about 'falling' damp (rain) which occurs above the DPC. Surely this would cause the same symtoms that 'rising' lol damp causes ????
Im not going to get dragged into another sticky on this one. A bit of common sense is required here :RpS_unsure:
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falling damp............................holyshit balls...........................where do we inject to stop that eddie.....................:-0
 
I've ALWAYS fixed the drip (whether beads or battens -oh yes :RpS_wink:) so that it's a fraction above the damp-course. And I've ALWAYS rendered to the ground - no comebacks, no damp bridging, no worries :-0
Maybe cos I use freeflo in both coats :RpS_scared:
Or maybe I've been lucky for the last 30 years :RpS_scared:



And now I've gone and posted in the general section for the "I've done loads of skimming but 'never really bothered' with rendering'' brigade to read :RpS_mad:
 
Falling damp is common on the older extensions. A typical say 1 story flat roof up to an existing outside wall. The outside wall above the roof takes in rain water and the dry bricks behind the lead flashing absorb this water down. You then see damp staining along the wall and ceiling line. The answer is to fit a cavity tray at the top of the lead flashing. A stinker of a job! Take 3 bricks out leave 3 bricks in, fit a tray and replace the bricks then next day do the same to the other 3 bricks to join the trays up.

I had to do it to my extension. I asked why could I not simply inject a dpc behind the lead? Apparently soft bricks like my LBC Cotswolds can absorb so much water, the water can pass right through and run down the cavity hence a tray.

same with damp around chimney breasts in attics. People think it is the lead work but quite often it is old porous frost damaged bricks taking in water then the dry bricks below draw the water down.
 
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johniosaif said:
Same as back to back stops, some insist on the flat and the design forgets to incorporate bricks under the dpc line, one job I'm going to tomorrow have to put brick slips over the blocks as the neighbour won't allow render plinth on their side
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yea similar but the way I sometimes do it u don't see any gaps,just plain render to the ground
 
Rigsby said:
Instead of back to back beads wouldn't expansion/movement beads be more reliable?
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Maybe, but if water sits in the joint and freezes - maybe that's why there's a few around here with the render breaking off either side of the beads/ Gotta be right with a drip bead every time:RpS_thumbup:
 
Rigsby said:
Falling damp is common on the older extensions. A typical say 1 story flat roof up to an existing outside wall. The outside wall above the roof takes in rain water and the dry bricks behind the lead flashing absorb this water down. You then see damp staining along the wall and ceiling line. The answer is to fit a cavity tray at the top of the lead flashing. A stinker of a job! Take 3 bricks out leave 3 bricks in, fit a tray and replace the bricks then next day do the same to the other 3 bricks to join the trays up.

I had to do it to my extension. I asked why could I not simply inject a dpc behind the lead? Apparently soft bricks like my LBC Cotswolds can absorb so much water, the water can pass right through and run down the cavity hence a tray.

same with damp around chimney breasts in attics. People think it is the lead work but quite often it is old porous frost damaged bricks taking in water then the dry bricks below draw the water down.
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This is penetrating damp . I wish I had your knowledge on modern renders, I don't but would love to learn (honestly mate, uncommon in the south but I really can see you're an expert in this area) but these Dpc things :-0 Not rocket science
 
its a british thing using drip beads you never see them in other european countries say holland and germany
 
right! its friday lets put an end to this madness.....................................................................................until monday
 
jesssop said:
right! its friday lets put an end to this madness.....................................................................................until monday
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Off now, collect my boy at six, minding him all day tomorrow ,stressful at times but I love him, not three till 11/11.14
 
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