Render over DPC

[doobstoo]

Sorry about this post, I know it's been covered on here a few times because I've searched, but yet to find an answer.

I have to bridge the DPC where I took out a step. The step was concrete and provided access from the French windows to the patio a few feet below. The step cracked quite badly over the winter and was beyond repair. I removed it and it seemed to be very damp all through. I'm left with exposed brick and the edge of a slate DPC (house is 1930's semi) and render either side. The plan, before I considered the DPC, was to render the stripped area and build a wooden step (I have plans for the patio later on so didn't want anything too permanent).

Then I considered that the DPC would be bridged. I think the answer is to apply a tar like sealant to the exposed brick and concrete. Is there an off the shelf product available that any of you could recommend please? I've no means of melting tar.

Upon coming to this realisation it occurred to me that the whole house is rendered over the DPC. Is this something I need to address? I've no damp problem I'm aware of and the render has been there some time. If not, do I need to bother with tar?

As well as asking questions regarding topics already covered, it appears I'm not good at writing concise posts! If you've made it this far I'd appreciate your thoughts. I've a picture but not sure how to post it.[/img]

 

[spada01]

It's pretty normal for the DPC to be rendered over. The render should contain a waterproofer and wont bridge over any significant amount of water

 

[hotrod]

It's pretty normal for the DPC to be rendered over.

No it's not. The DPC should not be bridged with render. There is a detail which allows for the render to continue below DPC, is this what you want to do? Regardless, do not bridge the DPC with render.

 

[Alastairreid]

Normal practice is to install a bellcast bead along the line of the dpc before rendering.
Having said that most of the older houses up this way have been rendered/cast over the dpc without a bead without any adverse effects. My own included.

 

[doobstoo]

Gents, thanks for the replies. You can appreciate my confusion.

Either side of the step is a continuous render all the way to the ground. I could put a bell caster thing in but it'd look odd as it'll only be the width of the step.

Is the water proofing you mention applied to the wall prior to rendering (like a layer of tar for example) or mixed into the render? If the later do you know of a name so I can look it up please?

 

[Alastairreid]

You put the waterproofer through the render mix.
http://www.permagard.co.uk/render-additive-waterproofer.html

Personally i would paint the wall with a brush applied cold tar.
http://gardens.taylorschoice.co.uk/products/137365_tar_paint_black_synthetic_5ltr.php

 

[doobstoo]

Thanks very much. I shall use both.