Ground floor feeling colder after floor insulation

[homemove]

Hello everyone.

I'm hoping someone could assist me with a bit of a dilemma. Around 2020, we carried out some renovation to our 1930's semi-detached home. As part of the renovation, the whole ground underfloor, which is suspended with a metre or less drop, was insulated with mineral/rock wool and netting to support it. The same wool was also added to our loft (room-in-roof).

As you can imagine, we did this in the hope that the house would be warmer.

However, for the last few years, we've noticed it's had the totally opposite effect. The whole house feels much colder. In fact it's warmer outside than inside. But one of the biggest differences we've noticed is that the whole ground floor is actually colder and draftier than the upstairs.

So it begs a million questions - what has gone wrong? What should I do to resolve this issue and why is our ground floor more colder than before? How can I find out what's causing the downstairs rooms to feel much colder? Could it be due to the ground floor vents?

Any of your suggestions and advise will be much appreciated.

Thank you in advance.

 

[Ivor Windybottom]

Were airbricks replaced or cleared at the same time? If so then it's possible that there may be more airflow underneath than there was in the past.

But this airflow is essential. If you have little or no air before then your floor was probably rotting away, so this was never sustainable in the first place.

 

[blup]

If the job was bodged, just a few inches of insulation with gaps, and the netting has sagged, it won't have made much of a difference. The through flow of warmer air in summer under the void might have made it warmer. You will have to physically inspect it.

Blup

 

[homemove]

Were airbricks replaced or cleared at the same time? If so then it's possible that there may be more airflow underneath than there was in the past.

But this airflow is essential. If you have little or no air before then your floor was probably rotting away, so this was never sustainable in the first place.

No the airbrick have not been replaced or cleared. But when sitting in the living room near the suspended floor airbrick, I have noticed that the skirting and floor (which are slightly higher than the level of the airbrick) are very cold in winter and there is a bit of a draft coming up.

If the job was bodged, just a few inches of insulation with gaps, and the netting has sagged, it won't have made much of a difference. The through flow of warmer air in summer under the void might have made it warmer. You will have to physically inspect it.

Blup

Apologies, but what issues exactly am I looking for under the floor?

 

[blup]

No the airbrick have not been replaced or cleared. But when sitting in the living room near the suspended floor airbrick, I have noticed that the skirting and floor (which are slightly higher than the level of the airbrick) are very cold in winter and there is a bit of a draft coming up.


Apologies, but what issues exactly am I looking for under the floor?

You will be able to assess its condition and take pics. There isn't a simple answer until then.

Blup

 

[homemove]

You will be able to assess its condition and take pics. There isn't a simple answer until then.

Blup

That's fine. It maybe a while before I can get back to you. Thank you for your help.

 

[George_engineer]

Further to the other comments, there are possibly issues with humidity and interstitial condensation. I would get two or three humidity and temperature sensors off Amazon and get some objective measurements on how the house is performing.

 

[^woody^]

"Feels colder", or have you actually taken temperature readings? How we feel heat is subjective, and we do confuse draughts with coldness too.

When you insulate a timber floor, you alter the heating dynamics and heat is reflected (which is why a floor may feel colder because it is no longer absorbing as much heat), and convection currents are created in the room as warmer air rises. Also, the air paths within the floor are blocked and so any gaps in, or more commonly around the floor perimeter cause air to move through those gaps faster making draughts more prominent. In addition, the warmer internal air draws the colder underfloor air in to the room and cooler air from elsewhere too, so increasing draughts.

You may or may not feel the draughts, but it will cause air in the room to move, and this can create the perception of the room being colder than it actually is.

Fundamentally, insulation does work and the room will be retaining more heat. But you need to deal with the draughts and gaps to remove the feeling of coldness.

 

[homemove]

Thanks @George_engineer and @^woody^

I've taken your comments on board and will order a few humidity sensors. If it was just me feeling it, I would put it down to 'maybe it's just me', but when I've got family members and friends complaining of the same issue, I feel there's more to it.

I understand what you're saying with regards to dealing with draughts that is coming through the edge of the floor. How do I deal with that? The skirting along the floor is very cold, almost like having a radiator running along the room that is not radiating heat, but actually cold air.