Anybody using Velox ?

[D Walter]

H Alexphd1, we used a mixture of timber bracing (vertical and diagonal) and also used some of our spare acrows.  We have literally never had any spare time after a pour to check and correct as by the time you get round the walls the first sections poured are hardening.  We have used electric and petrol driven pokers and no problems with them.  As mentioned above, our only issue has been not having an appropriately sized concrete pump.  Picture attached.

[Alexphd1]

what was wrong with the pump?

[D Walter]

We could not get a small enough nozzle and could not get an even flow of concrete. The concrete came thumping out so we needed to pour onto a moveable shute to take some of the energy out.

[Alexphd1]

Their is always something!

 

Our icf supplier could supply us a nozzle branded a "mudsnake" but luckily the pump guys had a suitable nozzle (5 inch I think)

 

We used 2 different pumps one for the icf  walls and one for the slab. The second had a concrete shut of at the end of the boom, this made stopping and starting very easy. A tip for anybody else pouring icf walls! 

 

 

Edited October 30, 2018 by Alexphd1

[scottishjohn]

tlaked to the man from velox and it does look like a good system for the self builder ,

costing seem less than durisol and comparable and cheaper than  some  poly icf types --but looks much stronger 

could be alot cheaper by time you looked at poly bracing system and costs and would seem to be as flexible as your imagination  for shapes you can do .

also the floor system is attractive for basements /garages under living accomdation 

still looking for the downsides

If you know any don,t be shy  

[D Walter]

Not sure I can think of any particular disadvantages but as a first time builder I have nothing to compare it with.  Clearly, with any concrete walling system, you have to get everythig right first time as it's very difficult to change once cured. 

 

As I have said previously, we did not manage to get a suitable concrete pump and that made pours more difficult/take longer but I suspect that problem would have been exacerbated with other ICF systems which have compartmentalised voids for the concrete.  We did take extra precautions such as lots of bracing with timber and acrows before pouring. 

 

We also cut little squares of plywood and screwed them over intersections where vertical joins met horizontal joins to keep the faces "true" until the concrete had cured (you can see some of these if you blow up the attached pic and the pic in one of my previous posts above).  As such, we did not trust totally in the wire ties supplied with the Velox system.  My builder said these squares of plywood made a big difference in keeping the walls 100% true right across the planes.

 

My builder was a little bit concerned about cold bridging in a couple of areas around the foundations but that is largely down to the engineering rather than the system.

 

There are some swings and roundabouts, for example with 180mm of insulation outside the concrete thermal mass (great for utilising solar gain) we will need to bolt right angled steel plates to the outside end of the concrete first floor to support the massively heavy triple glazed lift and slide panes at first floor level, which effectively sit predominantly on unsupported EPS.  I don't have a good picture to illustrate this but if you look at the attached pic. you can see the horizontal cast beam which will be supporting the much smaller triangular windows under the first floor eaves.  Inside the external 35mm Velox cementboard face is 180mm of EPS, then 150mm of concrete then another 35mm inside face of Velox cementboard.   The triple glazed triangular windows will, again, largely be supported on the 180mm of EPS supported by shear strength and the 50mm Velox cementboard reveal strips below.  This is less of a concern here but the larger rectangular lift and slide panes below will require greater support. 

 

 

 

We did end up with some very congested rebar (see pic) but that was due to my decision to go for cast beams and columns rather than RSJs.

 

 

 

I did see a question somewhere as to the relationship with the supplier of Velox.  I found him extremely helpful and easy to get hold of.  I always contacted him on his mobile and if I could not get through he would call me back in short order.  He was also very helpful at looking through plans and giving suggestions/tips.

 

If anyone wants to see any plans/engineering drawings or details let me know.

[D Walter]

A further thought on the "swings and roundabouts" theme, if you are pouring an unsupported concrete floor (e.g. a first floor) you will need access to hundreds of acrows for in excess of a month to support the floor while it is curing (see pic). 

 

The acrows can also come in useful for bracing walls when pouring concrete and we purchased ours from a previous Velox builder introduced to us by Velox.  We will sell the acrows on in turn when we have finished with them.  An upside of the Velox floor is that we will be utilising the voids (195mm deep by 380mm wide across most of our spans) in the Velox first floor flooring modules to run the ground floor MVHR ducting.

 

 

[scottishjohn]

thank you for pctures ==

good help in decision making process

I would like your acrow props but think you might be a bit far away --maybe i do it like the russians --lots of small tree trunks --plenty of them in sotland  LOL 

 but still got planning to get sorted yet -- to convince then to allow more than a typical long 1 storey crofters cottage on the 1 acre site --they just crazy

could be going down the VELOX way - and maybe a basement-plot has lots of slope on it

 

Edited December 6, 2018 by scottishjohn

[Sue B]

We came across Velox on this forum and I really like what I see with the product.  Are there any builds near me at the moment?  I am in Christchurch, Dorset.  

[scottishjohn]

ring uk agent and ask them --they will know

[PeterW]

1 hour ago, scottishjohn said:

ring uk agent and ask them --they will know

 

.... which under GDPR, he shouldn’t be telling you unless he’s already asked their permission to do so .... ?

 

I’m interested in this system as it seems a blend of two or three of the methods but can’t see if they’re trying to engineer out the issues with ICF and Durisol. 

[scottishjohn]

and what issues would they be ?-

-seem to have got a pretty good system --simple to erect ,very little bracing needed --a  continuos concrete wall --no durisol webs which mean the whole thing needs rendering to make it air tight  the panels look far denser than durisol as well ,I tried  nailing a couple of durisol blocks together and it just broke bits off and no grip what so ever in the blocks .

.sample blocks from durisol 

no it does  look good 

[Sue B]

I spoke to the UK rep last week and he was overseas.  He asked me to email him which I have done but had no response so far.  Over the phone he mentioned builds in Devon and Hampshire.  Englsih was not his first language and his geography of "local" was different to mine.  We are East Dorset and I suspect we will be driving to Exeter to see a hotel being built out of the stuff.  I suspect the Hampshire build is the one by @D Walter on the Isle of Wight.  Are you up for visitors @D Walter if I can get dog sitters arranged for the day?

[D Walter]

Hi Sue B,

 

When I was researching I visited two builds in Hampshire in close proximity to Four Marks but both of those will be finished by now.  I would not be surprised if Marek has other builds ongoing in Hants.  You are very welcome to visit here on the IoW if you can't find anything more convenient for you.

David

[Sue B]

I spoke to Marek again today - his email to me with pictures of builds had not sent so I got a whole series of them today.

 

I can't believe that one of the builds was the Surf School on our local beach.  Less that 3 miles away and a beach that we visit regularly as our beach hut is within 50 feet of it!!  I must have gone up before we moved to that beach hut!

 

@D Walter - I'd love to come and visit.  It looks like you are nearing your shell completion so would love to come before you do your final pour.  Any idea when that pour is likely to be?

[D Walter]

Hi Sue B.  We did our last pour a couple of weeks ago now and are in process of putting up membrane and battens for cladding and getting ready to put the breather membrane on top of the rafters.  You are welcome to visit any time but the Velox part is completed now.

[D Walter]

Previous Velox builders I spoke to have praised Velox for ease of plastering .  We are looking at two options: 1) spray plaster; or 2) dry lining and skimming.  My concern with dry lining was that the wire ties used to join the Velox panels protrude approx 5mm (so we would effecively be introducing a layer of insulatiom between the thermal mass in the walls and the rooms) but on enquiring with Velox we were told there is no problem cutting the ties off on the interior and we could therefore screw plasterboard (possibly use high density plasterboard) hard against the Velox.

[scottishjohn]

our strap it out and get service void as well?

an extra layer of insulation ,maybe

but also another layer to smoooth any temp changes and maybe simpler service fitting 

any sort of plaster will increase insulation 

[D Walter]

Hi ScottishJohn, our reasoning is that we want fixability for cabinets etc and benefit of thermal mass and if we have any air gaps those features will be compromised.  We have 35mm of Velox cement board to chase out for services in any event.  The house has been designed around getting the benefit of the thermal mass (concrete walls and floors and glazed SW aspect) so we don't want to compromise that.

[dzhou11]

Hi @D Walter

 

I can see you're using velox's floor system. Can you put UFH pipes directly into the concrete? 

[D Walter]

Yes, ours is directly in the concrete and that is recommended (see pic attached).  Given that it means that there will be no self levelling screed, real attention is needed to get the concrete as level as possible.  The whole system also needs a good bit of time and attention to get it all set up in advance.

[D Walter]

The above pic may be of interest as it shows a) how we divided the flooring so we could pour, level and power float a section of flooring at a time, and b) shovelling concrete from an OSB sheet into the wall void as our pump was too brutal to pour directly into the void.  The attached pic shows the moveable platform we used for pouring concrete into the wall void, again because of the wrongly spec'd pump.

[scottishjohn]

https://econekt.co.uk/wp-content/uploads/2016/02/ECONEKT.-ICF-Elements-Brochure2.pdf

 

see page 23 --concrete funnel is available as an accessory .

isodom also loks like good system --

certainly the system with the most different types of panels  I hyave found 

from roof to foundations

Edited December 18, 2018 by scottishjohn

[D Walter]

Looks quite sophisticated.   Izodom and Velox are pretty much coming from opposite ends of the ICF spectrum.  Velox has a limited number of different elements, cut to size on site and with pull strength at a premium.  Izodom would, I assume, be computer modelled on the basis of the DWG plans given the number of different elements.

[scottishjohn]

yes it looks like the best quality blocks i have seen anywhere and far more selection of block types to choose from  and I like the 0.5sqm per block ..

but at same time i like the velox system for some things --

still away of making any decisions on final design  due to local planning etc.

and therefore way off getting budgets worked out for 2 systems

i,ve spent hours hunting videos on both systems and people building with them .

velox definately looks very DIY for russians + other eastern countries s etc out in the middle of nowhere with sod all tools + no heavy equipment-+ one man  and his dog building team -which  is a big positive in some ways .

still not convinced on burying  services in the walls  on any system -pretty sure i,ll be going for service void and drywall.which could be filled with insulation before drywall if you wanted

just seems simpler and more choices to alter spec as you go ,

I understand you fear the air gap with detract from thermal mass --

is this not more a case of decrimental delay --eg it smooths out speed  temp changes?

I like the way your builders have done the radiant flooring with the wood for doing final floating .

that looks easiest way for self build small team --eg 1 or 2 people to do it if not going for finished polished concrete floor 

 

 

Edited December 19, 2018 by scottishjohn