We have recently moved to a house in Adamstown and have about 66SQ M back garden. It is shaded by apartments in the winter but we do get sunlight in the summer. The lawn is usually very soggy and wet and the soil seems to be quite compact and clay. The lawn also has a couple of big bumps. I sprayed it with roundup 2 weeks ago and all the lawn is dead now. Following are the steps I am going to take. Please tell me if I am doing the right thing or not.1. Rotovate the whole lawn with a powerful rotovator (8HP) and level it.,3. level it again.4. Dig herringbone pattern trenches for the french drain. Put in perforated pipe and connect teh end of it to surface drainage.5. cover the pipes with pea gravel.6. once all done cover the whole lawn with rootzone sand mix to get 1 inch layer. Level it very very finely.7. Lay the new roll out grass or sow the seeds.I am planning to leave some space for flower beds. Can you please help me that if the above steps make sense or i am just thinking in teh wrong direction.
The key point to addres is the compaction which is preventing drainage. You might find that digging some holes through the compacted layer to soil underneath that drains better will suffice. You may not be able to drain into the surface water drains as this is generally not allowed. But you could make a soakaway pit.
More on this: https://gardenie.wpengine.com/gerrycategory/drainage/?id=5414
While the grit will help, you may not need to use it if you can get the draiange right.