Greenhouse drainage

Redcross

My greenhouse floods in wet weather. I have been advised to remove two rows of bricks from the side of the greenhouse where it slopes, dig a trench and fill with gravel.
I would like some advice on how deep I need to dig, I have dug to about 8" and I am finding pieces of broken brick amongst the soil. 
 Also I am unsure of whether I need to use 10mm gravel or 20mm
Any advice would be appreciated

Eldi_Dos

Hi , could you explain what bricks you have been advised to remove, is it bricks laid on the ground?

Depending on how much water is running into the area and the width of the trench  between 200 and 300mm (8 to 12 inches in old money) should be enough depth. If you are finding pieces of broken brick that are difficult to remove just dig round them and leave them in place.Once you are happy with the trench, when it comes to digging at this time of year just do a little bit at a time, it is time to pick your gravel.

The gravel really is a personal choice but I favour 10mm pea gravel as it is easy to weed when needs be.Just stir the gravel with a screwdriver and pluck the little weeds and their roots as you go along.

Doubt your greenhouse has flooded much this summer but good to get ahead before the wet weather returns.

FreeBear

A gravel filled trench will work fine on a free draining soil. If you are on thick heavy clay, a perforated pipe in the base of the trench may be needed - This would be connected to a suitably sized soakaway via standard 100mm drain pipe.

Redcross

Thank you for your advice. The bricks I referred to were laid to form a path down the side of the greenhouse.They have been taken up so the trench is the width of the two bricks.
I have removed some of the brick but will try to loosen as much as I can.
Thank you again for your input

MACKEM99

You have rain?😁