We ( Father In Law & I) have just laid a base (3 to 4" rubble and the rest concrete), for a summerhouse and in certain parts it is showing signs of MINOR cracking. There are only 4 cracks and the longest is approx 6" and are fine 'hairline' type, probably due to overworking the concrete, it was 'sheeted up' to prevent rapid drying. What is the best way to deal with these before the summerhouse arrives next week? I was thinking to angle grind them out and fill with a mortar mix, they will not be seen as they will be under the summerhouse, but my Father In Law (it's his summerhouse) thinks silicon sealant will do the job! I don't mind which but I don't want to have to dismantle a summerhouse in a couple of years to relay the slab due to frost damage, I would prefer to sort it now.
TIA
John