Insulated Doors for Converted Garages

The Largest Wall in the Room

In a converted garage the door is usually the biggest single surface in the space, and on an uninsulated hollow steel door it is also the least insulated thing in the house.

A west-facing steel door takes sun all afternoon and radiates it inward for hours after. Whatever heating or cooling is in the room is working against that.

Two Ways to Fix It

A purpose-built insulated door. Two steel skins with a core between them. Where that core is polyurethane foamed in place, it bonds to both skins and turns the section into a structural panel: better insulated, considerably quieter, and stiffer so it holds its shape over years of cycling.

A retrofit kit. Insulation panels fitted into the existing door. Cheaper, noticeably better than nothing, and less effective than a purpose-built door because the panels are not bonded and the section gains little stiffness.

Retrofit kits also add weight, which matters. Springs are wound to counterbalance a specific door weight, so adding several kilos across the door leaves it unbalanced. That has to be corrected or the opener spends every cycle doing work it was not designed for.

On R-Values

Manufacturers quote R-values inconsistently. Some quote the insulation material rather than the finished assembly, which flatters the figure considerably.

For a converted room in Long Beach, whether the core is bonded matters more than a couple of points of R-value. A bonded polyurethane section outperforms a higher-quoted polystyrene one in practice, and it is much quieter.

Noise, Which People Underrate

A hollow steel section is a drum. Every roller crossing a joint resonates through it and into the room.

A solid bonded core damps that. Combined with sealed nylon rollers, and a belt drive or wall-mount opener where the room is used for calls or sleeping, the difference is substantial.

Seal First

We will say this on every visit: seal the perimeter before buying an insulated door. An insulated door over an open gap is poor value, and plenty of conversions are fixed by sealing alone.

If sealing gets you where you want to be, we would rather have done the cheap job well.

Call Dineoutsomalia at (562) 635-1330.