Timber frame then and now

[Alwayslearning22]

I used to erect timber frames about 17 years ago I can’t remember there ever being a vcl fitted, it was just insulation then we boarded it and rarely was it foil backed . We always fitted a breather membrane though.  
Is it because of increased airtightness that they’re needed now? 

My current new build has had the vcl drilled and screwed into by the blind fitter adding those safety clips for the cords. 

will this have any affect on the timber frame and insulation going forward?

[SteamyTea]

8 minutes ago, Alwayslearning22 said:

I used to erect timber frames about 17 years ago I can’t remember there ever being a vcl fitted,

My timber frame is 35 years old and it has a VLC. 

So did the Barret ones that 

9 minutes ago, Alwayslearning22 said:

blind fitter

(expletive deleted)ed up in the 1980s

[Alwayslearning22]

So No reason to be concerned about the punctures in the Vcl? 
thanks for your reply 

[Nickfromwales]

19 minutes ago, Alwayslearning22 said:

So No reason to be concerned about the punctures in the Vcl? 
thanks for your reply 

You’d only have the slightest of concern IF the screws were put in and taken back out again, and even then the issue would be almost inconsequential afaic. 
You can relax good sir  

[ProDave]

Timber frames have varied and evolved over the years.

 

1970's timber frame would be 4" frame and lucky to have anything other than 1" of rockwool in the frame and 3/8" non foil plasterboard straight onto the frame.  Often found to be rotten and perished in bathrooms and kitchens.

 

A 1980's-90's would still be a 4" frame but more likely fully filled with rockwool and with or without a VCL but usually foil backed plasterboard.

 

About early 2000's most were increasing frame size to 6" and full fill with rockwool. Use of VCL still seemed optional but foil backed PB was normal.

 

Only now are proper taped air tight layers and proper service voids sometimes being used, usually by self builders.  Prior to service voids, the frame will have been drilled for services usually with no regard to sealing holes so there will be holes opening to the loft and under floor void.  My pet hate on a windy day in winter is you unscrew a switch or socked and get an icy cold blast of air coming out of the hole.

[SteamyTea]

49 minutes ago, ProDave said:

My pet hate on a windy day in winter is you unscrew a switch or socked and get an icy cold blast of air coming out of the hole.

Tell me about it.

Only got once socket, on an interior stud wall, that does it.

Just can't seem to find the path it is coming in.

[Alwayslearning22]

Thanks for the reply’s lads.
My house was built by a developer so I’d say it’s likely that the vcl isnt even properly sealed to begin with. No point in me worrying about small holes is there. 

Edited February 15, 2022 by Alwayslearning22

[SteamyTea]

1 minute ago, Alwayslearning22 said:

My house was built by a developer so I’d say it’s unlikely that the vcl is even properly sealed to begin with. No point in me worrying about small holes is there. 

Well not small holes.

 

The main problem is because airtightness was vastly improved (generally) over traditional building techniques, condensation started to become a real problem.

Because of the movable nature of gasses, condensation generally happens on the nearest cold surface.  So windows first, then 'somewhere within the wall'.

As timber can rot after a few years, there is more moisture in the gas we call air (a mixture of many gasses, including water vapour), and the warmer the air is, the more fraction of water vapour is potentially in it.

To overcome this, a VCL is installed on the warm side, in the UK this means the inside. The rest of the wall is now only open to outside air, with its lower temperatures and absolute humidity, the actual grams of water vapour in every kilogram of air.  By also being 'vapour open' to the exterior, as the wall warms during the day because of solar energy and weather variations, the smaller amount of water can easily evaporate away.

But because there is now a trapped volume of air within the building, and one that has a greater absolute amount of water vapour in it, even if the relative humidity is lower, this has to be dealt with.

Window trickle vents and extractor fans were the usual method.  Whiles these work, the air changes are uncontrolled and spasmodic, and threw out the energy that had been put into the air to heat it up.  So mechanical ventilation and heat recover is now fitted.  This works best in a very airtight house and should easily recover the electrical energy to run them.

 

So how do you ventilate your house?

[Alwayslearning22]

 I have an Aereco dcv system in wet rooms, air inlet is through humidity controlled trickle vents. rh levels stay below 50.  
I try to open windows in the mornings.  

[SteamyTea]

1 hour ago, Alwayslearning22 said:

rh levels stay below 50. 

Should be alright then.

 

1 hour ago, Alwayslearning22 said:

I try to open windows in the mornings

I open my bedroom window at night, when I am generating humidity.

Never understood opening them after the event.

Edited February 15, 2022 by SteamyTea

[Alwayslearning22]

Makes sense but the wife doesn’t like it open at night. 

[SteamyTea]

9 minutes ago, Alwayslearning22 said:

Makes sense but the wife doesn’t like it open at night. 

To save the planet, I sent the wife back to her husband.

Other wives are available.