Porch Design

[markblue777]

Hi All,
Just designing my porch now as I am set to start the build in a couple of weeks and Whilst designing it I have struck what i believe is an issue.

The DPC is just under the existing door seal and so when i bring the brick work up to dpc I was going to do a suspended timber frame but using 2X4's (close centers and a small span so should be fine) so they are sent to dpc I obviously cannot put any board on to or finish floor.

Here is an image that hopefully explains it a bit more

is it a simple case that i can suspend them below dpc say 30mm so I can board and then finish floor so i avoid cold bridging.
(I will be dpc and then concrete under suspended floor to stop damp rising and stuff growing under it etc)

or should i just slab it, but if i do finished height would still come to same height and leave no room for finished floor.

Cheers
Mark

 

[blackrodd]

I'm a bit dim tonite and don't quite understand the question.
Have a look at this link, It's a sketch of what we are trying to achieve.
http://www.constructiontermsx.com/damp- ... efinition/

Regards Rodders

 

[markblue777]

Hey rodder,
I was looking at doing an suspended timber floor but after now looking at some pictures I have seen the bottom of the joists for a suspended timber floor sit at dpc level.

With this being the case the floor would sit above the houses floor. So I think I need to slab the porch to bring it to the correct level.

Cheers
Mark

 

[MMUK]

Yes you can suspend the joists below dpc level. As long as the dpc is unbroken and tucks into the house damp course it should be fine.

Normally the joist would sit with the top face at dpc level.

 

[markblue777]

Hi MMUK,

From what I saw online you can take the dpc up vertically so it is behind a course of bricks that sit on the dpc so you dont have to tie it into the house, is that correct?

do I overlap the damp proof membrane over the dpc then that should "secure it" correct?

what do you mean about as long as the dpc is not unbroken.

Cheers
Mark

 

[markblue777]

Hey All,

Here a a couple of new pics. In the image I am going with the concrete floor. it is below the dpc and what i assume is the dpm would come from under the floor and lap over the dpc. the red indicates the dpc level (and the vertical climb that i read about that can happen)

another question is how I can go about doing my roof.

so here is one idea i had

then the under side

the rectangle in the porch is the door (the brick opening, the door opens into the house)

as you can see with how the roof is above a joist (2X4) goes over the door opening a bit

I am just trying to work out other options for a roof. I cannot join onto the existing as that is over 3m high and would require planning permission

This is it without a roof, on the left had side of the roof is the lowest point of it all

anyone got any ideas, that dont look a pigs ear?

Cheers
Mark

 

[n0legs]

Mark if you don't mind me saying.
I would go get planning permission so you could add to the existing roof and not have the lean to style abutting it.
Sorry mate your house your rules and all that, but I'm not sure how that would look.
Apologies if I've offended.

 

[markblue777]

Na fair enough nolegs, thats why I am just trying to work out how I could go about it. I may be able to get my misses nephew round at the weekend who is a roofer to get a few ideas off him, but thought I would put it to the forum as well, to see if anyone had any bright ideas.
Cheers
Mark

 

[Lons]

Hi MMUK,

From what I saw online you can take the dpc up vertically so it is behind a course of bricks that sit on the dpc so you dont have to tie it into the house, is that correct?

do I overlap the damp proof membrane over the dpc then that should "secure it" correct?

what do you mean about as long as the dpc is not unbroken.

Cheers
Mark

+ 1 to what's been said.

Only point I would make is that it isn't normal to bring the dpm up and over the dpc. You would do the opposite!
The dpc would be usually oversize ( I use 300mm ), you would fold the dpm up the wall to dpc level and fold down the excess dpc to form a sealed envelope into which you pour the concrete. Don't cut the corners of the dpm btw, just fold it in.
Easier to do than to explain.

Bob

 

[n0legs]

Handy book here Mark for groundworks.
Page 29 for DPM and DPC.
http://www.pgsurveyors.co.uk/media/1868 ... t_book.pdf

 

[markblue777]

ah thanks nolegs, looks like a decent book having a quick glance through. thanks

 

[markblue777]

Some more roof designs I have been messing with

roof 2

roof 3

roof 4

The misses likes roof 4.

The porch is going to be clad in wood (prob pine) and painted. So the porch will look very added on so a bit of an abstract roof could add to the look I am envisioning. But on the same note it needs to fit, if that makes sense

cheers
Mark

 

[MMUK]

Hi MMUK,

From what I saw online you can take the dpc up vertically so it is behind a course of bricks that sit on the dpc so you dont have to tie it into the house, is that correct?

do I overlap the damp proof membrane over the dpc then that should "secure it" correct?

what do you mean about as long as the dpc is not unbroken.

Cheers
Mark

+ 1 to what's been said.

Only point I would make is that it isn't normal to bring the dpm up and over the dpc. You would do the opposite!
The dpc would be usually oversize ( I use 300mm ), you would fold the dpm up the wall to dpc level and fold down the excess dpc to form a sealed envelope into which you pour the concrete. Don't cut the corners of the dpm btw, just fold it in.
Easier to do than to explain.

Bob

Much easier to do than explain lol.

What I would do is try to chase the house wall in the dpc course but underneath the membrane so that your porch membrane can be slotted in under the house one.

 

[MMUK]

Forgot to add that your picture showing dpc for the brickwork is fine.

 

[markblue777]

Ahh cheers thanks MMUK