I'd like to extend my flat with a new single storey extension.

 

A section of the roof is a shared party structure with the upstairs flat / neighbour (who are tenants).

 

The neighbours will want to use part of the roof as a walk on terrace with tables and chairs, plants etc, which is fine.

 

I just need to design it in with a structural engineer to take the load, and choose  the most hard wearing low maintenance finish to the roof, that is tenant proof!

 

So options I'm considering on a concrete deck as a base with insulation on top are:

 

1) GRP walk on grippy membrane

2) Paving on small pedestals 

3) bitumen / polyurethane type membrane (hot applied)

4) cold liquid applied membrane

 

 

If the roof terrace belonged solely to me, I would do paving slabs on pedestals, as it's the nicest looking solution. 

 

However, as the roof terrace will be used by the neighbours, who do not have a good track record with maintenance - what is the best  solution?

 

Or am I missing other options?

 

Look forward to any advice / suggestions!

 

Edited July 24, 20233 yr by dodgems2023

Paving - reduce chance of accidental damage to the roof covering. Will also reduce sound transmission. Assume you think planning will be ok with an overlooking balcony? Some LAs despise them.

 

Edited July 24, 20233 yr by Conor

Hey Conor, 

 

Yes, there is already an existing terrace / big landing with 1m high metal balustrade over an outdoor storage room below.

This will all be demolished and replaced with a full width single storey extension.

Part of the new extension that replaces the existing landing, will be at the same height. The rest of the extension will be higher (3m) and only accessible for maintenance.

 

Instead of metal balustrading, Im thinking of proposing 215 x 1500mm high parapet  walls / guarding for privacy.

The Local Authority will probably want 1700mm high privacy screens, but there isn't any in the existing - so I think it's unreasonable.

 

Unfortunately the 1700mm privacy screen will probably be a Planning Condition - I just need to figure out how to get around it  🤔 Any ideas??

 

I spoke to Sika who advised best surface for trafficked roof terraces used as amenity spaces and furniture are:

1) Cold applied felting with pavers on pedestals on top ( warm roof build up)

2) liquid applied membrane ( cold roof build up)

 

I just need to check if there is a 3rd Option, with a bitumen / asphalt / liquid applied floor finish, suited to variable loads and high traffic on a warm roof build up.