The Brew Cabin

Posted: **Fri Apr 24, 2020 10:23 am**

Hi all,

I know this topic has been fairly well covered however I have just laid a 20sq m patio and all seemed to be going well. 100mm type 1 sub base, mortar was mixed at 4-1 etc.

2 days later about 7 of the slabs I can lift up quite easily. 2 of which are rocking so I am already aware they will need re bedding.

As for the other slabs that are just not stuck. Will the pointing be enough for these as they are still on a full and level bed of mortar albeit not stuck down?

Any help would be greatly appreciated.

Jon

Posted: **Fri Apr 24, 2020 11:03 am**

It's likely your mortar bedding was too dry, which is nor ncessarily a bad thing, but if you need the adhesion, then you ought to use a Bond Bridge Slurry Primer

You *cannot* rely on pointing to hold flags fast.

How to re-seat - https://www.pavingexpert.com/faq_fix_loose_flags

Posted: **Fri Apr 24, 2020 2:04 pm**

Thank you for the quick reply!

In hindsight I should have use the SBR slurry mix to help adhesion! Iâ€™ll get some ordered to make sure the loose stones donâ€™t give me any problems in the future.

Is it always better to go slightly wetter than dryer when mixing mortar? I was worried about getting it too wet which is where I may have gone wrong.

Posted: **Sun Apr 26, 2020 11:29 am**

There's a range of 'slumps' centred around S2 which give the ideal consistency for any particular installer. However, While I might prefer a slightly lower slump (drier) others will go for a higher slump (wetter) because that;s what suits them. Each of us finds a consistency that works best for us.

If you aim for a moist mix (S2) and see how that goes. If you find it too dry, or even too wet, adjust the water content on the next mix and, eventually, you'll find the consistency that is right for you.

Slump - https://www.pavingexpert.com/conc_slump

Bedding Mortars - https://www.pavingexpert.com/layflag3#slump

The Brew Cabin

Not all slabs stuck down.