Start of major work - perfect damp-proof for pre-war terrace?

[gasket]

Hi folks. I've just completed my first move on the property ladder - I took a 1907 mid-terrace back to brick and refitted it. I'm about to start my next one - an identical house on the same street. I did all the work myself on the first but on the next one I want the standard to be much higher (and quicker) so I'm employing the pros.

The house is a real hovel and needs even more work than the first. It will go back to brick again - rewire/replumb/replaster/windows and a new roof before refitting (there's plenty of margin to cover the work).

On the first house I had problems with damp and condensation - that one had the downstairs walls membraned and plaster boarded which prevented the damp from brickwork coming through, but the house still felt a bit clammy at times.

So, I thought I'd ask here - for a house like this what would be the full belt-and-braces approach to ensuring that no damp/condensation can occur? This would be factored in at building stage when the house is a bare shell.

Mid-terrace, built around 1907, with double-skin solid brick walls (no cavity), two chimney breasts and fireplaces downstairs.

The modern things I'll be adding (which I appreciate don't help with older houses) are:

• double glazing
• felted and re-slated roof
• loft insulation.

I don't want to render the outside.

I was thinking something like:

• crawl space under the downstairs floor cleaned out to remove any build-up of soil against the walls and to ensure good airflow. And soldier walls under floor made good while I'm at it (lots of lost mortar and loose bricks) - all-but free and good practice as I'll be down there anyway.
• Check vents into this area are sufficient for airflow
• Inject damp proof (carefully chosen)
• Insulated plasterboard (VPC integrated) to front and back walls of the house
• Tank or membrane the adjoining side walls prior to plaster
• Trickle vents in new double glazing
• Tumble drier vented outside
• extractor hood in kitchen and powered vent in bathroom
• I'm having the outside of the house blasted and repointed, so will make sure they use an appropriate mortar

I've read quite a lot on this and understand the importance of airflow so open to suggestions - I've considered things like the simple Permavent vents in the walls up to the more costly, but still reasonable, EnviroVent ventilation systems with heat recovery.

I'm unsure about the chimney - once again I'll be fitting period cast-iron fireplaces. In my last house these were decorative and I capped the chimney but not sure that this is the best approach.

I like the area and there is enough margin in the house to cover the work.

Any advice for a future proof approach would be mod welcome.

Thank you.

 

[flameport]

crawl space under the downstairs floor cleaned
Check vents into this area are sufficient for airflow
Tumble drier vented outside
extractor hood in kitchen and powered vent in bathroom
I'm having the outside of the house blasted and repointed, so will make sure they use an appropriate mortar

All good, and you can add others such as not drying clothing, towels or anything else on radiators and actually opening the windows.

Inject damp proof (carefully chosen)
Tank or membrane the adjoining side walls prior to plaster

A useless waste of money.
Injected DPCs acheive nothing, and even if they did, the house has managed perfectly well for over a century without one.
The adjoining walls will not be a source of damp unless your neighbours are in the habit of regularly washing their internal walls with a garden hose.

Insulated plasterboard (VPC integrated) to front and back walls of the house
Trickle vents in new double glazing

If you want, although the vents are only required if you are sealing the rest of the house up.

Damp occurs due to outside or inside sources.
For outside, ensure the walls are properly maintained, gutters, drains and the like are not blocked, seals around window frames and doors are good, plants and other vegetation is not allowed to grow against the walls, etc.

For inside it's providing suitable ventilation and ensuring those that live there use the property correctly.
Unfortunately there are those who consider it essential to make houses as airtight as possible, making mould and rot inevitable.

If you are fitting fireplaces, leaving the chimney open at the fireplace and fitting a vent cap on top will probably provide all the ventilation required.

The fans and similar devices are usually installed to compensate for the persons living there doing all the things they should not, such as drying their washing inside, taping over the bathroom extractors, taking lengthy boiling hot showers several times a day and never opening the windows.

 

[gasket]

That is incredibly helpful - thank you very much!