foam sealing vs gap

[omph]

Is there any practise around using foam when installing doors/windows ? Historically, that space was left as is to allow for expansion and contraction. However, in this age that just seems irresponsible especially when it comes to efficiency and heat retention. Expansion foam is the obvious solution but then how does that effect expansion/contraction of the window/door ?

 

[Wayners]

Foam is soft. Will have some give.
Makes window airs tight plus hold it in.
I remember watching widow fitters in Louisiana just using foam to fit storm windows. Bit of trim around and jobs a good um

 

[robinbanks]

I prop mine up true/square/plumb with wedges and foam them up, then when the foam has set, fire some concrete screws in for a mechanical fix

 

[omph]

Thanks for the responses.

Is there any difference between low/high expansion foam ? The foam expands in the direction of least resistance so I've never understood those who are averse to using the high expansion stuff.

 

[robinbanks]

Perhaps some people can't easily judge how much to use, they overfill the gap with HE foam and end up with large quants on the floor to clean up. It also has a habit of squeezing out a gap then a blob breaks away and rolls down a vertical surface leaving a trail as it goes. On painted windows the solvent in the foam can attack the paint leaving a mark even when the foam is cleaned off

 

[crank39]

You would think foam would expand in the direction of least resistance which to a point is true but I've known it to still bow frames slightly especially door frames

 

[omph]

You would think foam would expand in the direction of least resistance which to a point is true but I've known it to still bow frames slightly especially door frames

How many of such occurrences have you observed ? and were you the one doing the foaming ?

 

[crank39]

Couple of times around 30 years ago when I first started in the fitting game I made those mistakes especially no fines, those frames just got foamed in and left, no fixings, as well as cleaning woodgrain pvc with pvc solvent cleaner, that didn't end well. More recently as a service engineer I probably see once a month bowed doors due to foam especially Persimmon new builds

 

[omph]

Couple of times around 30 years ago when I first started in the fitting game I made those mistakes especially no fines, those frames just got foamed in and left, no fixings, as well as cleaning woodgrain pvc with pvc solvent cleaner, that didn't end well. More recently as a service engineer I probably see once a month bowed doors due to foam especially Persimmon new builds

Thanks. Do you know if the new builds were foamed before or after the fixings ? I would imagine if the door is properly secured with fixings before the foaming that bowing would be practically non existent.

 

[crank39]

The frames I'm coming across are fixed in on cleats and fixed into the internal skin and plasterboarded over, no visible fixings through the frame and as the regs say the frames need to be set back further for better protection from the elements it would mean standard frame fixings would go through the cavity closer and not into brick

 

[omph]

The frames I'm coming across are fixed in on cleats and fixed into the internal skin and plasterboarded over, no visible fixings through the frame and as the regs say the frames need to be set back further for better protection from the elements it would mean standard frame fixings would go through the cavity closer and not into brick

How far back do they need to be set ? I didn't know this