We used an external wood glue (polyurethane? Might have got that wrong
). It expands to fill the gaps, and sets very solidly and can be sanded if necessary. Others on here have used bathroom type fillers.
I only 'clean' the coup about once a fortnight, ie everything out, spray with poultry sheild (providing I think it will dry - depends on the weather), and replace paper, woodshavings with fresh, adding Diatom powder. Shavings in coup are not there as bedding, girls will ideally sleep on the perches, or if not, will get into the nest boxes. So coup shavings are purely to absorb poo.
I wash the plastic nest crates every weekend, replacing nesting with a base of woodshavings (absorbent) and top with a nest of straw (cosy). Again use Diatom and also add a sprinkle of louse powder - so they get a dose every time they nest.
On a daily basis, I pick poo out of the woodshavings. It's not what I would term as cleaning really. Just like picking eggs from the nest box, you pick poo from the coup
Also do a daily poo pick in the run. Just basic common sense hygiene really. Wouldn't matter if you missed a few days, but it's just nicer to be in the run if you don't have to tip toe through poo.
Here's a pic of pop hole, external and internal. Tilly (ex batt) still in need of feathers
Pop hole door is controlled by an automatic light sensitive door opener.
Below see original plywood insert being modelled by Wilma - looks the business certainly, but a sod to clean. Replaced with plastic crates which are a dream. Need to be v sturdy solid so can't be tipped up. These are workshop types store bins.
Coup raised well off the floor so don't encourage rats, also good place to hang feeders so they don't get dirt kicked into them, and can't be knocked over. Also good for shade - whooo hoo, the suns out!!
Contour of bitumen roof provides ventilation at the right height, but fill in gaps with weldmesh to keep out rats.
Have a compost bin handy for poo/bedding. My garden compost bays are in here too, which the girls love. Their bin is the darlek, and the rubber gloves are their for a purpose
.
And don't forget your own perch........you'll need it! Sunflower kneeling mat is perfect for the job, and I keep it on top of the coup when not in use.