Should I fit Cavity Trays at DPC level?

[iDIY]

Hi Guys,

I am building a garage with an art studio above it. I mention this because the garage part doesn't come under building regs but the studio does?

Anyway, 1m deep foundation trench, 250mm concrete then 3 layers of foundation block are all done. The garage floor slab is poured on top of a DPM which covers the compacted aggregate and sand layers.

The DPN cones up the sides of the slab and over the top of the first course of the inner leaf.

I am now ready to start laying block inner leaf on top of the DPM. The brick outer leaf will be played on a DPC 150mm above ground level. There will be 65mm insulation in the 90mm cavity.

Q: Do i need to install cavity trays between inner and outer leaf around the whole construction at DPC level?

 

[acurachris]

You only need cavity trays at DPC level if you’re installing a radon/gas barrier. The trays slope any captured moisture in the cavity to the outer leaf weep holes.

Generally, a normal cavity will continue down past DPC level to your cavity fill (225mm below DPC).

 

[^woody^]

I mention this because the garage part doesn't come under building regs but the studio does?

What about the garage walls, foundations, floor/ceiling?

 

[iDIY]

What about the garage walls, foundations, floor/ceiling?

The garage floor (slab) doesn’t come under BR, foundation and walls do because they will hold up the art studio. But the garage walls don’t have to have insulation because no need for garage to comply with thermal insulation requirements. Roof of garage will require double plasterboard (fire) and insulation to keep floor of studio within BR.

 

[^woody^]

The garage floor (slab) doesn’t come under BR, foundation and walls do because they will hold up the art studio. But the garage walls don’t have to have insulation because no need for garage to comply with thermal insulation requirements. Roof of garage will require double plasterboard (fire) and insulation to keep floor of studio within BR.

You are building a structure that contains a garage and a room above. It all needs to comply to any applicable standards. The walls for instance, still have to comply with other criteria irrespective of any requirement for insulation or not.

 

[iDIY]

You are building a structure that contains a garage and a room above. It all needs to comply to any applicable standards. The walls for instance, still have to comply with other criteria irrespective of any requirement for insulation or not.

That’s what I said?

 

[Leofric]

Roof of garage will require double plasterboard (fire) and insulation to keep floor of studio within BR.

You mean the ceiling of the garage , the roof will be over the studio won't it ? Don't you just build the lot to comply with bldg. regs

 

[iDIY]

You mean the ceiling of the garage , the roof will be over the studio won't it ? Don't you just build the lot to comply with bldg. regs

Im not going into the detail, but half the area of the top of the garage is garage door the other half is ceiling/floor so technically your right in the wording. However, my architect and the BCO stated the garage are does not have to comply with insulation requirements so long as the insulation between upper area and garage is insulated as it will be. That said i am insulating the garage because I want to use it more as a workshop rater than somewhere vehicles will go in.

 

[Leofric]

I am sure the people commenting on here know which parts need to be insulated and which don't ( as far as possible from the information provided ) but if you have already engaged an architect on the project why not ask them for clarification on construction details ? What do the working drawings show regarding dpc's ?
p.s. will the workshop be heated ?

 

[iDIY]

**

 

[Leofric]

 

[^woody^]

What did I miss? Lol

 

[^woody^]

Anyway, if this Architect designed what do the plans say about cavity trays?