Bit of help with DPC/DPM, sketch included

[damanpunk]

I've started drawing up a replacement garage but I'm not sure what way to go with the DPC/DPM. I'm a structural draughtsman to trade so I don't know much about the wood and bricks side of it!

The garage FFL will be a good bit below the houses DPC (approx 600mm ish), what would you recommend doing with the DPM here? I thought cutting it off at the FFL then a few coats of a paintable DPM might work?

At the boundary end my neighbours garden is quite built up (street is on a hill which also doesn't help), again probably 600mm ish higher than the garage FFL. Is what I've sketched ok for the DPM/DPC at this end?

If the details are ok what would you recommend for protecting the DPM? Would timber stud work (only fixed to the blocks above the DPM and overhanging it freely) be ok? Would it then be worth insulating the stud work and plastering over? Or would it not be worth the hassle as the front and rear of the garage will be ventilated?

Thanks in advance

 

[pinenot]

I would extend the dpm with a self adhesive membrane and the insulation up to the line of the house dpc. Also protect the insulation with plaster board slips for protection. Cut out and expose the air bricks, cap the slot with a plaster/metal vent cover. By doing this you'll avoid any cold bridging and allow the continuity of ventilation to the house...pinenot

 

[damanpunk]

Thanks for the reply buddy, sounds like a good idea with the insulation actually. Do you think the detail at the boundary end would work ok? I've been looking at external tanking details tonight but sure if it's maybe a bit OTT

Also, do you think it's worth insulating the whole thing when a lot of heat will probably be lost through ventilation? I'll definately do the slab as it's too difficult to do later but not sure about the walls yet and whether I should draw them with a cavity.

 

[pinenot]

Garages are normally single skinned as you may know, but more and more people are lining them and making a more integrated unit with their house, what your proposed usage is, I do not know.
One suggestion assuming you'd rather not go down the full insulation road, would be to duct the air brick thereby retaining positive venting to the house and none to the garage.
Flat duct/trunking could be buried within the strip of wall insulation and with an offset angle from the air brick located wherever it suits!

 

[damanpunk]

Found this, might be an option for venting the solum underneath the slab?

 

[pinenot]

All sorted...trific