Strip footing and eps slab for timber frame?

[DragsterDriver]

 

I would prefer an eps raft/slab but-

 

waiting on planning permission and then turnaround time on a slab design and delivery could be financially crippling- I really do need to ‘hit the ground running’. I have easy access to plant and groundworkers/bricklayers who owe me favours ?

 

for a timber frame bungalow with cladding- no external masonry-

 

has anybody built or seen detail for traditional strip footing with a concrete block plinth and thick eps slab internally? it’s the need to ensure continuity of insulation by way of an upstand linking to the timber frame. 
 

https://imgur.com/gallery/QuPdVgC

 

apologies for the sketch quality- I woke early thinking about bridging loans ?

[Oz07]

Have you heard of the insulating blocks? Perisul or marmox or whatever they are? Think most use these in this situation.

[DragsterDriver]

14 minutes ago, Oz07 said:

Have you heard of the insulating blocks? Perisul or marmox or whatever they are? Think most use these in this situation.

cheers I’ll have a look!

[Russell griffiths]

I’m not sure why you think there will be a hold up, 

you put your planning in to build a house, not the foundation design. 

Get a soil survey done now and get the foundation designs done now, then when you pass planning you are ready to go, 

2 days to site strip and start setting out. 

 

I had my place demolished about 4 days after planning passed. 

 

Make sure you have the cil levy signed off so you can start.  

[DragsterDriver]

25 minutes ago, Russell griffiths said:

I’m not sure why you think there will be a hold up, 

you put your planning in to build a house, not the foundation design. 

Get a soil survey done now and get the foundation designs done now, then when you pass planning you are ready to go, 

2 days to site strip and start setting out. 

 

I had my place demolished about 4 days after planning passed. 

 

Make sure you have the cil levy signed off so you can start.  

the danger is planning changes = new footprint, new calcs and design of raft. Having said that depends on when Kore or whoever can deliver if it was a designed raft?

 

 

[SuperJohnG]

Kore as I understand it now don't sell direct to UK people, they want to sell through agents (due to brexit). I got mine just before Xmas and think it's been a pain since then. 

 

@Thorfun I think may have a better update? 

 

there are others like econekt and isoquick. Both considerably more expensive though for me. 

[DragsterDriver]

6 minutes ago, SuperJohnG said:

Kore as I understand it now don't sell direct to UK people, they want to sell through agents (due to brexit). I got mine just before Xmas and think it's been a pain since then. 

 

@Thorfun I think may have a better update? 

 

there are others like econekt and isoquick. Both considerably more expensive though for me. 

it’s that sort of scenario I dread- but without final Plans and paying for calcs I won’t know delivery ? 

[Thorfun]

42 minutes ago, SuperJohnG said:

Kore as I understand it now don't sell direct to UK people, they want to sell through agents (due to brexit). I got mine just before Xmas and think it's been a pain since then. 

 

@Thorfun I think may have a better update? 

 

there are others like econekt and isoquick. Both considerably more expensive though for me. 

this was exactly my experience with Kore. in the end the groundworks company are just laying pieces of EPS rather than having a pre-cut version from a supplier like Kore/Isoquick/Ekonekt etc. they seem happy to do it that was and as long as I get the thickness and compressive strength as designed I'm not fussed how it's achieved!

[DragsterDriver]

11 minutes ago, Thorfun said:

this was exactly my experience with Kore. in the end the groundworks company are just laying pieces of EPS rather than having a pre-cut version from a supplier like Kore/Isoquick/Ekonekt etc. they seem happy to do it that was and as long as I get the thickness and compressive strength as designed I'm not fussed how it's achieved!

what sort of design do you have? That’s the sort of alley I may be heading down. I can easily get dug out and concreted ‘to dpc’- and lay EPS as a slab if designing and ordering a kit is problematic.

[Thorfun]

20 minutes ago, DragsterDriver said:

what sort of design do you have? That’s the sort of alley I may be heading down. I can easily get dug out and concreted ‘to dpc’- and lay EPS as a slab if designing and ordering a kit is problematic.

by design I presume you mean foundations? if so, the basement and main house is sitting on an insulated slab (250mm thick) comprised of 200mm EPS300 underneath and 200mm EPS100 up the outside of the walls. The 'arm's of the house that are not above the basement are on 2m deep trenches down to the bedrock and then 300mm EPS300/100 laid with a 200mm slab on top.

 

I used TSD for my structural design and they use Kore as their insulated slab of choice so it was all designed as a Kore solution. but it is just EPS so as long as I get what's required if the groundworks company don't want to use a pre-cut solution that's fine by me. They're aware of my requirements and the tolerances to work to for the timber frame and happy with it all.

 

you can check out my blog for more details on some of this stuff. 

 

 

[DragsterDriver]

27 minutes ago, Thorfun said:

by design I presume you mean foundations? if so, the basement and main house is sitting on an insulated slab (250mm thick) comprised of 200mm EPS300 underneath and 200mm EPS100 up the outside of the walls. The 'arm's of the house that are not above the basement are on 2m deep trenches down to the bedrock and then 300mm EPS300/100 laid with a 200mm slab on top.

 

I used TSD for my structural design and they use Kore as their insulated slab of choice so it was all designed as a Kore solution. but it is just EPS so as long as I get what's required if the groundworks company don't want to use a pre-cut solution that's fine by me. They're aware of my requirements and the tolerances to work to for the timber frame and happy with it all.

 

you can check out my blog for more details on some of this stuff. 

 

 

Thanks I’ll keep an eye on the blog  

 

for the non basement area will you have courses of block lined with eps rather than the preformed eps formwork?

[Thorfun]

2 minutes ago, DragsterDriver said:

Thanks I’ll keep an eye on the blog  

 

for the non basement area will you have courses of block lined with eps rather than the preformed eps formwork?

no (at least not if I understand the question!). it will be the same as the Kore system just not preformed and not using the 'L' shaped pieces of EPS at the edges. e.g. This is how TSD designed it using the Kore system for the above ground arms:

 

you can see the insulation sitting on the trench fill with the slab poured within the insulation. but we won't be using the 'L' shaped pieces with the upstand at the edge. at least that's what I believe at the moment. we're definitely not using 'L' shaped pieces on the basement so I presume it's the same above ground although that could all change.

 

 

 

 

 

 

 

[DragsterDriver]

6 minutes ago, Thorfun said:

no (at least not if I understand the question!). it will be the same as the Kore system just not preformed and not using the 'L' shaped pieces of EPS at the edges. e.g. This is how TSD designed it using the Kore system for the above ground arms:

 

you can see the insulation sitting on the trench fill with the slab poured within the insulation. but we won't be using the 'L' shaped pieces with the upstand at the edge. at least that's what I believe at the moment. we're definitely not using 'L' shaped pieces on the basement so I presume it's the same above ground although that could all change.

 

 

 

 

 

 

 

Thanks!

 

that’s what I’d like in an ideal world- not sure how I’d be able to resolve not having the premade eps formwork L shape?

[Thorfun]

should say that all of this will/should be designed by your structural engineer. what works for one might not work for another and might be overkill for someone else. 

[Thorfun]

1 minute ago, DragsterDriver said:

Thanks!

 

that’s what I’d like in an ideal world- not sure how I’d be able to resolve not having the premade eps formwork L shape?

take the base layer out beyond the slab and put up stands of EPS? if you're concerned then just get a company to design a pre-cut version. takes the risk away. it's been almost 5 months since Brexit so maybe the initial teething issues I hit have been resolved by now. you never know unless you ask.

[Thorfun]

also, just to add, our groundworks company are going to be using Stylite EPS and they also do the L shapes so maybe we will be having them above ground. I'd better add it to the list of questions I have for them but as we need to get the basement built first that stage is months away.

 

https://www.styrene.co.uk/view_full_product/passive_foundation/stylite_passivehaus_foundation.html

 

sorry for the confusion on this! reading back it seems I don't know what I'm talking about.....which is probably true!

 

I do know 100% for sure we're not using 'L' shaped pre-cut pieces for the basement as this is what's being done.

 

 

for the above ground I'm not exactly sure what will be being done. so I apologise again for the confusion. now I look at the SPI website and see the L shape pieces maybe we are doing that above ground after all.

Edited April 25, 2021 by Thorfun
added an apology for being a bit rubbish!

[Thorfun]

2 hours ago, DragsterDriver said:

the danger is planning changes = new footprint, new calcs and design of raft. Having said that depends on when Kore or whoever can deliver if it was a designed raft?

 

 

I agree with @Russell griffiths and get everything done while waiting for planning. yes it is a risk if they don't approve then you'd have wasted money and have to get things redone. but if you're in a rush then those are the risks you'll need to take. otherwise, you'll have to wait until planning is approved and then get all the calculations and designs done. 

 

for us it took about 8 months after planning approval to get the building regulations drawings done and submitted. but our build is pretty complicated with all the different aspects that need to be considered. I'm sure a simpler build wouldn't take so long.

[DragsterDriver]

21 minutes ago, Thorfun said:

I agree with @Russell griffiths and get everything done while waiting for planning. yes it is a risk if they don't approve then you'd have wasted money and have to get things redone. but if you're in a rush then those are the risks you'll need to take. otherwise, you'll have to wait until planning is approved and then get all the calculations and designs done. 

 

for us it took about 8 months after planning approval to get the building regulations drawings done and submitted. but our build is pretty complicated with all the different aspects that need to be considered. I'm sure a simpler build wouldn't take so long.

thanks, I’ve dropped styrene an email to see what their lead times are on components  

 

regarding the build- I wish I had an actual ‘build thread’ where I could lay it out better.

 

the situation is that I’ll complete on the plot in around 3 weeks but my architect hasn’t submitted my planning yet- he will this week even if I have to kidnap him but that’s already a 6 week delay if planning actually perform on time ?-

what I can’t do is then wait on lead times for a manufacturered eps raft kit- I really have no

idea what their timescales are ‘because covid etc’. Maybe I can get a typical detail, as long as the footprint of the place doesn’t change too much.

 

I have 12 months bridging against my home in which to build the new place but I’ll market mine as soon as I’m out of the ground and move in whatever the condition but it’s all a big old risk. I am a builder so I can work fairly quickly full time on it, but it’s not the best impulsive idea I’ve ever had...hence a strip footing I could have pulled out and concreted in days with me stick building  rapido. Again, I have a mate who can build the kit but I just don’t think I have the time to wait. 

 

Edit:

 

building reg plans I can work on a building notice which is handy.

Edited April 25, 2021 by DragsterDriver

[Thorfun]

sounds like a risky and stressful situation! I wish you the best of luck with it all.

 

as much as I love the idea of the insulated slab (and it appears you do too) it just might not work for everyone. and so maybe a more 'traditional' approach to the foundations would suit you better so you're not so reliant on the lead time for the EPS and you can get the foundations and block and beam floor in and then worry about insulating as the build progresses? as far as I know you can still detail the potential cold bridges out using that route (although I am in now way a builder or very knowledgable in all of this!) so it might be worth considering.

[Russell griffiths]

@DragsterDriver. Do you have any form of planning in place?

 

I had a house on site so was applying for a replacement dwelling, in the end with all the surveys it took 16months to get planning. 

 

When I had a topo done I told the surveyor I would be building that summer, he looked at me and chuckled and said you won’t stick a spade in the ground this year, 16months later. 

 

You might be really lucky, but just be prepared for how slow these council wallys are. 

 

If I had to do this again I would sell up as soon as I could to free up money and move into a mobile home, we have been selling a house in London to finish our place and it has taken over a year to sell, obviously Covid shit messed things up, but we could get another lockdown. 

[DragsterDriver]

9 minutes ago, Russell griffiths said:

@DragsterDriver. Do you have any form of planning in place?

 

I had a house on site so was applying for a replacement dwelling, in the end with all the surveys it took 16months to get planning. 

 

When I had a topo done I told the surveyor I would be building that summer, he looked at me and chuckled and said you won’t stick a spade in the ground this year, 16months later. 

 

You might be really lucky, but just be prepared for how slow these council wallys are. 

 

If I had to do this again I would sell up as soon as I could to free up money and move into a mobile home, we have been selling a house in London to finish our place and it has taken over a year to sell, obviously Covid shit messed things up, but we could get another lockdown. 

yes! 
 

there is discharged planning for a potton bungalow on the plot so there is a ‘fallback’ position which helps massively. Water is on site, shared septic tank with neighbour, electric on site from the abandoned build in 2004.

 

I could at a push modify the original plans a fair bit on ‘S96 and S73 applications’ apparently which although not ideal would get me out of jail if I’m in the brown stuff.

 

I’d have gone the mobile home on site  route 100% but sadly I’ve two teenage kids PLUS my old Mum lives in our annexe. 
 

it was an impulse idea that’s snowballed...

 

edit:

 

somehow I’ve used many text sizes ??‍♂️

Edited April 25, 2021 by DragsterDriver
Fonts!

[SuperJohnG]

5 hours ago, Thorfun said:

 it's been almost 5 months since Brexit so maybe the initial teething issues I hit have been resolved by now. you never know unless you ask.

I would hope so as it would silly for them to make it difficult.  Econekt (who supply izodom) seems to be bringing stuff still so can't imagine why Kore can't.

[gravelrash]

just had my design signed off by SE- just visual inspection of ground trial holes. Using Galaxy insulation for EPS cut to size as required

 

 

.21-093 01P2 Structural Plans and Details (A1).pdf

[Gus Potter]

12 hours ago, DragsterDriver said:

 

I would prefer an eps raft/slab but-

 

waiting on planning permission and then turnaround time on a slab design and delivery could be financially crippling- I really do need to ‘hit the ground running’. I have easy access to plant and groundworkers/bricklayers who owe me favours ?

 

for a timber frame bungalow with cladding- no external masonry-

 

has anybody built or seen detail for traditional strip footing with a concrete block plinth and thick eps slab internally? it’s the need to ensure continuity of insulation by way of an upstand linking to the timber frame. 
 

https://imgur.com/gallery/QuPdVgC

 

apologies for the sketch quality- I woke early thinking about bridging loans ?

Hi Dragster.

 

You may be over thinking this. Often a standard perimeter edge insulation for a slab is say 25mm thick. If you want you could increase the slab edge insulation to just behind the inner face of the finished plasteboard. Use a good quality say PIR insulation.. looks like you could get 75mm in here.

 

Yes, you may get a little reduced performance but you will face structural issues on how you tie the kit down. Keep it simple and decouple the kit from the slab structurally and insultaion wise. Simplify the design, thus make savings which will allow you to offset any percieved reduced performance at the slab kit interface elsewhere.

 

 

[DragsterDriver]

2 hours ago, gravelrash said:

just had my design signed off by SE- just visual inspection of ground trial holes. Using Galaxy insulation for EPS cut to size as required

 

 

.21-093 01P2 Structural Plans and Details (A1).pdf

thanks! That’s really helpful-

I’ll look up galaxy