elias837

Yes, it’s reasonable to ask, if steel is being charged cost-plus. If it’s fixed price, they don’t have to show invoices. Cost-wise, £28k supply + £10k install for that scope isn’t unusual. Check quantities against drawings rather than expecting full invoice transparency.

Yes, that’s very likely why. You’ve exposed bricks and mortar that were never meant to be below ground or regularly wet. Old mortar washing out makes it worse, as it lets water sit and wick up by capillary action. Before, the path probably acted as a crude barrier. Now rain is hitting exposed, porous brickwork directly and soaking in. Channel drains are still the right idea, but you’ll also need to repoint those joints and ideally add a small gap or drainage layer between the wall and path. Make sure finished levels stay below the DPC and water is directed away from the wall.

On an old house like this, the gains really start showing once you combine airtightness work with decent insulation boards rather than just weatherstripping. I’ve been doing similar bits room by room and finding suitable materials locally was a pain. Online Insulation had the sizes and densities I needed for retrofit (rockwool slabs, PIR, insulated plasterboard) without having to deal with the DIY sheds’ limited stock. Worth a look if you’re going that route.