DIY two storey extension

[Chickenski]

HELP! I am a woman self building a two storey extension.
Need help with connecting old DPC with new one. There is absolutely no way to expose the old DPC; it is just crumbling! Building inspector demands it overlaps by 100mm. What shall I do?
I am also confused about Celcon Solar/Standard. Celcon website clearly says Solar is best to be used inside. inspector is advising Solar outside and Standard outside!
Ground floor is suspended timber. What size joists??

I have already referred to this forum several times. Ohterwise I would have been on Valium!

More tips the better so please help.

 

[noseall]

do you not have an architect/designer/drawings!

 

[Chickenski]

I have the drawings detailing concrete floor. However, I was advised by Building Inspector to construct suspended wooden floor rather than solid concrete. So timber for ground floor is not specified.

Connecting old DPC wit the new one should not be difficult. However, the house is old and whatever is left there comes out in pieces thus not allowing me to have 100mm overlap!

Of course it would have been easier to have a builder. But I haven't.....

 

[Chickenski]

Come on! Help please, we need to get DPC ready tomorrow morning.

 

[noseall]

forget the overlap. explain to b.c. that it is not feasible and that
by removing masonry you are doing more harm than good.

 

[Chickenski]

May be a bit difficult to tell BC I am not going to do it. Would not wish to antagonise them at this early stage....

 

[noseall]

logic would be on your side here.

if removing the mortar joint or the brick itself, is causing the existing dpc to break down, then one can only assume that leaving well alone is better than vandalism.

butted dpc is acceptable. we do it all the time.

 

[Chickenski]

sorry to sound ignorant. what is butted dpc???

 

[noseall]

butted, is a new dpc that meets an existing dpc without tying it in. it is just...er ..well... butted up.

 

[Chickenski]

This is what I wanted to do today. However was told it HAS to overlap!

It is just a beginning and I am really disheartened.

In addition I was told that my windows are too big i.e. ratio of floor to glass. I thought I can overcome this problem by having Argon gas filled glazing which produces 1.1 UValue. Much better than one prescribed by building regulations (1.8). Oh no! They want the whole insulation business recalculated from the beginning!

What do you do?

 

[noseall]

What do you do?

we use/recommend a very good local architect, who is rather switched on when it comes to seeing things from the builders and the homeowners point of view.

all these niggles can be sorted by a decent professional and they can liaise directly with b.c. on your behalf.

 

[Chickenski]

Thanks for your advice Nosall!!!!
Of course it would have ben easier to hire somone very professional. I didn't and this project is now my challenge.
BC approved the dpc this morning. So good news at last. I am laying DPC tomorrow and have another question. I can see there are two schools: one to lay in without covering the cavity and another one that says it is OK to have DPC stretching the width of the wall including cavity, in my case 290mm.
Do you think it is OK to go with the second method?

Thanks

 

[alpcon]

I really think you should have bit the bullet, swallowed the expense and submitted a full spec to building control in this way all these little niggles could have been sorted before you started.

In fact a good architect would have eliminated all of these problems for you. I have no doubt you will have lots more to sort out along the way and your extension could take a very long time to finish.

However we are here to help so keep your chin up and ask away.

Best to lay in the DPC - one on the inner skin and one on the outer skin and leave the cavity clear

Just out of interest are you physically building this extension yourself or have you employed a builder

 

[Chickenski]

Thanks again! No I am not physically building it; I have a bricklayer and a joiner/roofer working together. They are from Poland and are not up to date with BR. Before you say anything, they are excellent, work hard and do what I tell them to do. They in fact told me not to build a solid engineering brick wall. Well, I thought I knew better. We now demolished it and put up cavity from the foundation.

We had architect/structural engineer. Of course we had to: this extension has a lot of steel beams and columns going in. However, the architect was crap and omitted things like ventilation to bathrooms, smoke alarm etc from the plans. If you want to I can send you a link to my plans which are posted on Richmond-upon-Thames website.

The thought of today is: how big joists for suspended timber ground floor??
Would 7inch suffice? Or may be less? We do not have a lot of space. How dense sleeper wall?

Keep me alive please!

 

[NS215]

sack the poles and get someone in who knows what they are doing to abide by local planning

they maybe cheap but by the sounds of it lots of hassle

CHEAP ISN'T ALWAYS BEST!!!!!!!!!!!!!