How long before I remove acro props?

[pilsbury]

Thursday is steel beam fitting day. Have removed several bricks to insert supports and acro props and will then cut out the required bricks below to take the beam. Once it's sitting nicely on the padstones (I don't intend to bed the beam on mortar) I will pack mortar into the gap between the beam and the bricks above 4:1 mix. Ok?

How long before I remove the props? 24 hours? More?

 

[John D v2.0]

More than that, after 24 hours you can still scratch it with a finger.
I'm dryish packing under our back door at the moment and I've left it 4 days before unpacking it

 

[pilsbury]

Bloody hell. Renting acros.

 

[^woody^]

You should be slate packing, which means if the bearings and padstones are dry and there is not loads of replaced bricks above, then you could potentially take the props out straight away.

*Woody accepts no liability if the whole lot falls down.

 

[John D v2.0]

They're pretty cheap given the cost of getting it wrong surely?
Dry mix takes longer to go off, and you should be using minimal water to avoid shrinkage. 24 hours, try making a small batch of dryish mortar now, pack it into a block, then see how it is tomorrow night. Then make your mind up. If you pack it tight enough you might be OK.

 

[pilsbury]

Will try a test batch of mortar.

Woody, padstones are well set. When you suggest slate packing, I intend to do this between the padstones and beam, but are you suggesting between beam and brick above too to take up any gap in differing levels?

 

[tomfe]

Yes

 

[chappers]

always pack your brickwork above the steel with slate as Woody suggests.
It tightens the brickwork above back up if any of it has moved slightly