Wet weather and mortar

[LSB]

It was dry this week, shouldn't have believed it, but HID laid first layer of blocks and now they have got wet.

He has covered the top, but is worried about the mortar being affected by the damp.

 

Is this an issue or will it just take longer to set hard as it still seems quite soft today, or is it because it's covered and it needs air.

We have been told not to let the blocks get soaked hence covering them loosely with a tarp.

 

The usual 1 step forward 2 steps back 😞

 

FYI blocks are 3.6n H&H and these are the ones that will be below the DPM.

[Radian]

46 minutes ago, LSB said:

Is this an issue or will it just take longer to set hard as it still seems quite soft today,

Unless there was so much rain that it purged the cement from the sand, it'll be fine. The mortar sets through a slow chemical reaction that takes place in the presence of water. Drying out before this process is complete is the main danger. Also freezing which makes the water expand, so wrecking the matrix - but you have neither of these concerns. Covering with a tarp won't have any adverse effect. One thing it can help with is to retain the heat given off by the exothermic reaction as it sets.

 

Mortar can remain quite soft for a few days but actually achieves good compressive strength nonetheless. In fact, its load bearing abilities can appear within hours. It will depend greatly on the ratio of the mortar mix. What was yours? e.g. 5:1 sand/cement? 

[Dave Jones]

no issue at all. trenches often have a couple inches of water in them when conc is poured for example.

 

The problem is when face brickwork is not dry and it rains, struggle to ever get the staining out of the courses below.

[LSB]

1 hour ago, Dave Jones said:

no issue at all. trenches often have a couple inches of water in them when conc is poured for example.

 

The problem is when face brickwork is not dry and it rains, struggle to ever get the staining out of the courses below.

as we are cladding / render then at least we don't have to worry about this.

After all there are plenty of things that we do need to worry about.