Beam and Block floor and ventilated void vs Timber Frame

[BartW]

Good morning,

 

We are currently at the point of building a foundation for our next house, and have come to a stumbling point.

 

We previously had an external brick skin to the plinth which was providing a route, and a way of dressing the telescopic vents. We later removed that external skin, as concluded it was costing a lot of money, by not doing anything structural (our timber frame sits fully on top of the 140mm 7kN blocks).

 

This leaves us with a question of how to address the ventilated void. Telescopic vents will have nowhere to be hidden externally, and there will be no way / point to install the vent grilles.

 

How has everyone else been addressing this? One of the neighbours is proposing bollard vent system on theirs, but I find this would be in the way of all things around the property.

 

Any ideas please?

 

Thanks

Bart

 

[George]

It is better to keep the outer leaf up to floor level, this gives the cladding something to meet up with that won't rot and gives the telescopic vent somewhere to sit. 

[ETC]

  On 11/05/2022 at 06:11, BartW said:

Good morning,

 

We are currently at the point of building a foundation for our next house, and have come to a stumbling point.

 

We previously had an external brick skin to the plinth which was providing a route, and a way of dressing the telescopic vents. We later removed that external skin, as concluded it was costing a lot of money, by not doing anything structural (our timber frame sits fully on top of the 140mm 7kN blocks).

 

This leaves us with a question of how to address the ventilated void. Telescopic vents will have nowhere to be hidden externally, and there will be no way / point to install the vent grilles.

 

How has everyone else been addressing this? One of the neighbours is proposing bollard vent system on theirs, but I find this would be in the way of all things around the property.

 

Any ideas please?

 

Thanks

Bart

 

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Get rid of the ventilated void and use precast concrete slabs rather than block and beam.

Edited May 11, 2022 by ETC
Additional information included

[BartW]

  On 11/05/2022 at 16:23, ETC said:

Get rid of the ventilated void and use precast concrete slabs rather than block and beam.

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Too late for this. We are where we are. Any other options that work with BB?

[Nickfromwales]

  On 11/05/2022 at 20:56, BartW said:

Too late for this. We are where we are. Any other options that work with BB?

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So what is your rain screen going to be then?

[BartW]

We are proposing vertical + cross battens, then open charred timber facade. 
 

by the way, when browsing I found this last night. I think I will run it passed BC:

 

 

 

 

[ETC]

Looks like a very clever detail. You might need drainage in the floor void.

 

Get rid of the void by infilling the height difference between the infill block and the beams with insulation. Fill the sub-floor with hardcore, lay a bed of sand, lay a sacrificial DPM, lay the beams, infill the base with insulation and lay the blocks. Would this work?

[Faz]

I don't see how that vent works as it is below ground level and will have no airflow....

[DragsterDriver]

Interested to see what building control say? 

[Simplysimon]

with b&b floor presumably 2 x dpm due to isulation, how much water is going to come up through. i was under the impression you could lay b&b on the ground.

[Roundtuit]

  On 12/05/2022 at 06:27, BartW said:

by the way, when browsing I found this last night. I think I will run it passed BC:

 

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Great on paper, but blocked up with crap within a couple of years I reckon.  Is it too late to keep the outer leaf up to dpc level as suggested by @George ?

[BartW]

  On 12/05/2022 at 21:07, Roundtuit said:

Great on paper, but blocked up with crap within a couple of years I reckon.  Is it too late to keep the outer leaf up to dpc level as suggested by @George ?

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It's not, but I find paying extra £6k for that a privilege I can spend money on elsewhere (like "overnight" steel price increases that amounted to that and a bit...)

[Tom84]

What did you do in the end? I'm currently looking at the same issue. Also, how to protect the end of beams from moisture?

[BartW]

  On 23/05/2024 at 18:56, Tom84 said:

What did you do in the end? I'm currently looking at the same issue. Also, how to protect the end of beams from moisture?

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So I extended the vertical sleeves up and cut them into the charred timber cladding, then bought metal decorative grilles that have got a fine mesh and pretty much do not obstruct airflow vs designed air brick flow.

 

Patio level is up as well, so it looks really clean.