Crucial difference between posi joists & easi joists

[willbish]

Just noticed on posi joist spec that the space between the flanges on their slimmest joist (202mm) is 108mm, therefore not big enough for a 110mm soil pipe?!?

 

Easi joist on the other hand, slimmest joist 195mm and 125mm between flanges.

 

I have been through several design amendments with the posi joist dealer but seems that was all in vain.

 

 

Edited January 28, 2019 by willbish
Inclusion of 'not'

[PeterW]

Is this brick and block or timber frame ....?

 

if it’s brick and block, go with the 225mm joists as they course perfectly with blocks - you don’t need to cut splits to fit them. My supplier doesn’t spec the smaller joist unless absolutely necessary for this reason.  

[willbish]

It's ICF.

 

What I'm struggling to understand is, why design a joist that can't fit a soil pipe through when the unique selling point of posi joists is that they are great for services!

[epsilonGreedy]

10 minutes ago, willbish said:

It's ICF.

 

What I'm struggling to understand is, why design a joist that can't fit a soil pipe through when the unique selling point of posi joists is that they are great for services!

 

 

This is because PosiJoist sizes PS9 and PS10 are the typical choice in a residential property.

 

What leads you to believe joist size PS8 is right for your design?

[willbish]

1 hour ago, epsilonGreedy said:

What leads you to believe joist size PS8 is right for your design?

 

It's not a belief it's a need.

 

I am rebuilding on the footprint of an existing cottage. Think low ceilings and low ridge height.

Ridge height cannot be increased due to local architecture. Upstairs rooms cannot be pushed further into the attic space due to the requirement to maintain volume of attic for bat roost.

 

The distances the joists need to span mean that PS8 were adequate, why use a deeper joist if you don't have to?

Architect even specified PS8.

 

It's no bother I'll just use Easi joist, 195mm depth, which have very similar span tables. I'll even gain 7mm but crucially will be able to fit 110mm soil pipe through the web.