I am purchasing a property & need to check out the sub floors with minimum disruption to the owners.

Hi Is there a cupboard under the stairs?if so you should be able to gain access under there and take a few boards up to have a look. Regards Steve

You have paid your fee for the survey, he should have given you a bit more info, as he is in a better position than the tradesmen here, as we havent seen the job. Although he says you have air bricks, what makes him think they are inadequate, are the floors bouncing or sagging. Only sure way for peace of mind is to take up some sections of floor, or cut out the air bricks and shine a torch in, although you wont see much. If the vendor wont let you do a closer inspection then allow a sum for the worst, ie new floors, timbers and extra air bricks.

If every room is laminated or tiled there is no easy way! Are there no rooms on the ground floor that are carpeted so you can roll back and lift a floor board? The floor may be sound and feel solid to walk on but through no ventilation it may be very wet on the oversite, this moisture will be in the air through being so warm and then this moisture will affect the timbers. But you may be lucky and it could be a very dry oversite with no issues. If you do purchase the property you have to add air bricks all round if possible,more ventilation the better. Good Luck Scott Cannon.

You will have to knock a hole maybe a few, in the external wall and view timbers from there. Rather than lift the internal floor up.