We've recently leased an office in a tropical climate and I am trying to figure out the best way to increase the insulation in the building.

This is the roof structure from inside

So far I've researched:

  • spray insulation (options are both inside and outside)
  • adding additional insulation between the steel beams

But still not sure of the best method. There is a steel roof above the thin layer of insulation that is present.

It's in the Philippines where it's an almost constant 22-32 degrees celcius, and we do plan on adding air conditioning, so the insulation is really to try and get the general temperature down to cut down energy costs.

  • 1
    Actually the added insulation will slow the thermal transfer across the outside to inside. What this means is that when you do add the air conditioning it will be more effective at being able to keep the inside cooler than the outside. On the other hand in a constant temperature situation the added insulation would do little to make the inside cooler. You have to start with it cooler inside in the first place. So for example if it is cooler at night and you start the day with the coolness of night inside the building and then close it up the added insulation (continued)
    – Michael Karas
    May 31, 2014 at 14:11
  • (continued from above) will keep it cooler inside longer then it would without the insulation. So keep this in mind as you plan the upgrade.
    – Michael Karas
    May 31, 2014 at 14:13
  • In most cases add insulation to a nonclimate controlled building will make it warmer. I would wait until you get the air conditioning.
    – DMoore
    May 31, 2014 at 14:42
  • Drop ceiling at the bottom of the trusses with R39 fiberglass bats on top and provide ventilation of the open space above the ceiling/insulation. Reduced radiant heat into the work area in addition to conserving the temperature of the cooled air. May 31, 2014 at 19:15

1 Answer 1


Spray foam insulation is one of the best options for insulating. It seals very airtight (losses from leaking air can be 40% of your energy bill) and can cover over metal and other materials that can "thermal bridge" and conduct heat from outside. It is expensive, and is generally applied by a professional which may put it out of your budget. It is also somewhat flammable and some areas require that it be covered by an ignition resistant material which might be difficult.

Next up would be solid foam panels tightly fit between the trusses. Third best would be more fiberglass batts like the ones up there already for a greater thickness. You are trying to increase the air tightness and the total R value.

  • It would be best yes, but it came it way over our budget. So we're looking at adding drop ceilings now, which is a bit disappointing but we'll see how it goes.
    – Chris
    Jun 9, 2014 at 3:36

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