Drylining new house pros and cons

I have looked at other posts and I havent seen an answer to what I need to know.

We are building a new house and can't decide whether to get drylining for the outside walls. A few people have recommended it to us but others are saying it a waste of money and that we are "insulating insulating".

We have put in excellent insulating in the interior walls so I am wondering if I am wasting 3-4 grand on something that is not needed.

Has anyone any opinions on this that could help me out, thanks!

what exactly is the make up of what you have constructed????

are you talking about a timber frame house???

personally, it's all pro's and no con's. I even 'dry-lined' my TF house. Makes wiring much, much easier.

not when 'dry lining' outside walls......

i think the poster is confusing it with something else...

no, I mean the outside walls too.

Again, it depends upon what you are building - there is a thinking now that if you have concrete walls that it is better to use insulation on the outside as internal dryling causes you to lose the thermal mass of the block.

heinbloed over on [broken link removed] is quite knowledgeable on the topic - you should do a dearch on that forum.

by dry lining, do you mean the installation of cement board with acrylic render on battens with insulation on the timber frame structure???

you have to be very careful if doing this to ensure the 2nd insulation complements the first.....

OP please tell us the make up of the exitign construction....

in my opinion 'drylining' is a process only of internal fitting......

Ohhh my inexperience and lack of knowledge is going to come through now, the missus's father is project managing it as he is a retired ex blocklayer!

Its a concrete house, all I can tell you is that he and the plasterer we have employed tells me there is no need to dryline the outside walls because the insulation we have inside will be more than sufficient.

However a friend told me the plasterer was always going to be against it as it makes his work more difficult!

is the construction a single leaf of a 9 inch cavity block wall, with insulation between timber battens and a plasterboard finish on the inside???

or is it 2 leafs of 4 inch solid block with 2 inches of insulation between the blocks???

I think what the OP is referring to is the practice of adding insulated plasterboard to the inside of the outside walls - in order to augment the (60mm?) insulation between the block leaves

this is relatively common these days (we did so), but bear in mind a few things:

* make sure the insulated board has a vapour barrier (we used xtratherm)
* two ways to fit - either specialised "mushroom" fixings hammered in or fixed to battens on the wall - see vendor documentation
* the extra thickness complicates window openings, boards etc. and the fitting of sockets, basins, skirting, curtain poles etc.
* if you have walls which are part external and part internal you'll either have a "step" or end up insulating some internal walls
* you'll lose the "thermal mass" of the concrete external walls (but not the internal concrete)
* need to be careful regarding potential interstitial condensation and cold bridging at the ceiling corners - we have HRV for vapour control

if this isn't what was meant, please ignore!

SSE

By outside walls, i think you mean external walls... basically you want to know if dryling the building envelope is a good idea????

This is a common practise and has many advantages, however....
I would be careful regarding the following points:
1. The insulation you incorporate should actually be breathable and NOT vapour barriered. If you install a vapour barriered insulation you effectively have a vapour proof sandwich which does not allow for the exhaustion of vapour within the space between the cavity board insulation and the plasterboard insulation. I would recommend a sheeps wool, rock wool, softboard, or hemp based insulation here.
2. Thermal mass of concrete is not really a huge issue as concrete losses heat very quickly... if you use something like softboard it would absorb solar heat during the day and release it slowly during the evening / night.. this is the preferred situation. Plus your concrete will absorb your space heating causing your house to heat up slower, a bad thing if you have UFH.
3. Your window and ope details become very important. But on the otherhand, as galwaytt states, you can create a service cavity which makes servicing easier.
4. you would definately need a Heat recovery system and not passive wall vents.

sydthebeat, why would you need a heat recovery system and not passive wall vents? (are window vents the same thing?)