Smell (of old) in the newly renovated house

[NewbieOnHolidays]

We moved into an old house 1y ago, did full renovation, but in a couple of bedrooms upstairs I still feel the old smell, similar to the smell we have up in the old loft. Where could it be coming from?

We didn’t do anything to the loft, just got rid of rubbish there. But renovated whole house: stripped all wallpaper, carpets, all walk in wardrobes, kitchen, bathrooms. Replastered, repainted, new wooden floor throughout with new skirting. New windows. Only a couple of doors are the old ones, but we painted them.

there are old air brick vents in each bedroom, we keep windows open throughout the day.

and one of the kids who is allergic to dust has constantly congested nose, although the house if free from carpets, any soft furniture, looks more like an operating theatre and we clean regularly, so I’m not sure where the dust and the smell are coming from.

would appreciate any advice

I would think there is some moisture and mould trapped somewhere behind your renovations.

I would get specialist advice.

Have you got any devices that can monotor the humidity level in your house? I have a Dyson air purifier which does that.

Thanks. We have air purifier, haven’t used it for a few years, can bring from loft and turn on.

tbh there was a fair bit of mould around windows and all the specialists we spoke with said they it’s all due to lifestyle (lack of ventilation, not opening windows). So we just took old wallpaper off and put new plaster over.

You said its an old house, how old?

Have you possibly used the wrong kind of plaster and paint for the age of the house?

It's possibly the spaces between the beams under the floor. Generally the upstairs floors never get completly lifted and the accumulate sits in the spaces between the floor and downstairs ceiling. You would think it would be sealed in there but not unless all the floorboard gaps are carefully filled.

House was built in 1930s. Would plaster/paint need to be different for 100yo vs 15yo house?

That’s what I thought was actually happening. The smell seems to be coming from old wood. It’s much more noticeable in loft, but I think it also comes from wooden boards between ground and first floor. There are gaps between skirting and floor

What does it smell like, is it damp? Rotting? I would be concerned about structural integrity of the joists if you can smell rotting wood.

There are pretty cheap thermometer/humidity level things on sale in places like Aldi at this time of year.

We also live in a 1930's house. In spring we completely renovated a bedroom including lifting the old floor boards to replace. I think they were original to the house. It was surprising what was under the floor - skeletal rodent remains (and we have never been aware of rodents), nasty dark thick dust mixed with a surprising amount of who knows who's hair, an old insect nest etc. It was pretty grim.
We cleaned it all out and replaced with engineered flooring. Its notable that now that this room is much less dusty during a clean than the other bedrooms - so I guess we will have to do those in the future too.

An old house would have white lime plaster (possibly over laths if they are internal walls) and should preferably be painted with breathable paint, although it's debatable exactly how breathable some of those paints claiming to be actually are.

Modern houses will have gypsum plaster (pink these days, although our Georgian cottage was reconfigured in the mid '60s when they applied a load of grey gypsum which was then the norm) and it's less of an issue to use modern vinyl paint.