Part timber framed building to brick wall help!

[fl00die]

Hi everyone,

I was wondering if someone can help and advise.

I have a very old small brick outbuilding in my garden. Id say about 5m2 maybe... 1 of the walls (the back wall) of this outbuilding makes up my boundary between the neighbours garden.

I am wanting to make a soundproof studio around 15m2 this spring and knock most of the existing building down keeping the boundary brick wall and one side. Ill extend both of these in brick then build the remaining 2 sides in wood. It is already sat on a concrete base but of course ill need to pour more to make the area I need... I will lay some DPM down over the enlarged slab then put the 2 stud walls on that and connect them to the 2 existing brick walls. (how I connect the bottom of the stud to the concrete without piercing the DPM is another question!)

My main question is, these walls are just a single brick thick (maybe even called 1/2 thick in the trade!?) so they probably get very damp. Is it wise to connect the wooden walls to this in fear of damp crossing into the wood?.

the Ceiling joists will also span from the top of the existing boundary brick wall to the front new stud wall. Where the joists meet the top of the brick wont there be another case of damp moving across?.

Im an office guy but like to get my hands dirty on projects but really have no clue when it comes to dampness etc?.

Thanks in advance

David

 

[^woody^]

Use a polythene DPM sheet to line the inner face of the brick wall.

There is no potential damp issue from the joist and wall connection, but you need to ensure that the roof perimeter is properly detailed with a fascia and drip. Look at flat roof construction details.

You can screw/bolt the bottom of a frame through a DMP with no issues.

 

[theprinceofdarkness]

"I am wanting to make a soundproof studio", this is your big problem. You need mass in the walls and door and ceiling and lots of sound absorbency, I think wooden walls is starting from the wrong place. Try 6" concrete high density blocks.
Frank

 

[fl00die]

Hi Woody - Crikey, that was quick! what a forum! thanks.

Yes I am looking to build a "warm roof". Room > Joists > OSB > Vapour control layer > Insulation > EPBM stuff

So, the 2 remaining brick walls are connected at right angles and recommend I use my 1 large piece of DPM to go across the enlarged slab floor / base and up the inside of both these brick walls terminating at the tops where the joists will rest yes? (Sorry just double checking things).

That is great to hear re: screwing through the wood > through the DPM and into the concrete base / upright brick wall. I thought if this DPM was pierced then damp could come up through the slight holes?!.

I am going to be making a room within a room to get the sound proofing I need. Would it be advisable that I first build a stud floor on top of the DPM which is ontop of the Concrete base?.

Thanks Woody and / or anyone who helps.

Rgs
David

 

[fl00die]

Hi Frank - thank you for your help/input. Yes ideally I would love to complete the 3rd and 4th walls as proper built brick walls but having to do foundations and the cost of the brick work could be just too much a job compared to enlarging the concrete base and erecting the stud walls. I like the idea though Frank, if you have any further thoughts its appreciated.

If it helps. My wall construction is planned as follows (from outside in) :

Red ceder cladding
2x1 batons
Tyvek breathable / waterproof membrane
OSB
10cm stud filled with rockwool
5CM air gap
10cm stud filled with rockwool
2 Layers of plaster board with Green glue in between
Skim and paint

I was going to use resilient bars before the plasterboards but the walls are already de-coupled so theres no point (supposedly)

 

[fl00die]

* Further notes: I am keen to use the existing boundary wall for a couple of reasons. Firstly, as frank says, brick is better for sound proofing, and Secondly I would need to remove the brick wall completely and install a fence meaning the new back wall of the studio would need to be at least a metre into the garden so I can squeeze down the back and Maintain back of the studio. If that makes sense