Most insulated trailers are insulated between the frames and nowhere else, which leaves every piece of aluminium square tubing running heat straight from the outer skin to the inner wall. Covering the tubing is what turns a pile of insulation into a system.
Aluminium is a conductor, not a sponge. It moves heat about a thousand times better than the air on either side of it. A trailer skin is thin, so it does not hold much heat on its own — it heats almost the moment the sun touches it, and a roof in Florida sun runs to 150°F while the air is in the eighties.
The frame is the highway. Aluminium square tubing runs from the hot outer skin straight through to the inner wall. Every crossmember is a bridge carrying roof heat inside, and insulation stuffed between the frames does nothing about it. This is the part most trailers get wrong.
The trailer is what stores it. The floor, the mats, the wood, the tack and the air soak heat up all day. That is why a trailer keeps getting hotter after midday, why it is worst in the late afternoon, and why it is still warm at nine at night long after the skin has cooled.
Do one and you get a real improvement. Do both and they compound — the roof stops most of the load arriving, and the insulation stops what is left from crossing the frame.
This page is about the second one. The roof coating covers the first.
Aluminium square tubing is a superb conductor. Insulate the cavities and leave the tubing bare and you have built a wall with a metal bridge every sixteen inches, each one quietly carrying outside temperature in.
That is why a trailer with batts in the walls can still feel like an oven, and why the inner skin is often hot to the touch directly over a frame member and cool between them. Run a hand across the wall on a hot day and you can usually feel exactly where the framing is.
Closed-cell tape over the tubing breaks that bridge. It is a small amount of material in exactly the place that was undoing the rest of the work.
Roof and wall heat arrives largely as radiant energy. A foil face reflects it rather than absorbing it, which is a different mechanism from the foam behind it and why the two together beat either alone.
One detail matters: foil needs an air gap facing it to reflect properly. Pressed flat against the skin with no gap it stops being a radiant barrier and just conducts. Installed with the gap it belongs against, it does the job it is sold for.
Foil tape over the seams keeps that reflective layer continuous, so there are no gaps in the barrier at every panel joint.
This is the one people underestimate. Horses put out a remarkable amount of moisture — breath, sweat, and everything on the floor. That warm wet air reaches a cold aluminium wall and condenses on it.
Open-cell insulation and batts soak that up, hold it against the metal and stay wet. You get rust from the inside out, insulation that has lost its value, and a trailer that smells.
Closed-cell foam does not absorb water and acts as its own vapour barrier. The moisture never gets into the wall to begin with.
The radiant load coming off the roof and the sunny wall is reflected instead of soaked up, and the frame is no longer feeding heat inward. The trailer stops climbing all afternoon.
Combined with a reflective roof coating the effect stacks: far less heat arrives, and what does arrive has no easy path through the structure.
The same system runs backwards and works just as well. Body heat stays in instead of conducting out through the frame, so the trailer holds warmth on a cold night haul rather than shedding it.
The bigger cold-weather win is condensation. An uninsulated aluminium roof in winter turns into the coldest surface in the trailer, and warm moist air condenses on it and drips back down onto the horses and the bedding. A properly broken and sealed roof stops it forming in the first place.
Bare aluminium panels drum. Foam bonded to the skin damps the panel and takes a noticeable amount of road noise and rattle out of the trailer.
Nobody buys insulation for this and everybody mentions it afterwards.
Because the tubing is the path the heat is actually taking. Insulation between the frames leaves every frame member conducting straight through, and that bridge can undo much of the benefit of everything around it.
To work as a radiant barrier, yes. Foil reflects radiant heat across a gap. Squashed flat with no gap it conducts instead, which is why installation matters as much as the material.
Both. In summer it keeps radiant heat out. In winter it keeps body heat in and, more importantly, stops condensation forming on cold aluminium and dripping back onto your horses.
Usually yes — panels, foil tape and closed-cell tape go over the existing structure. Tell us what the trailer is and we will tell you what it needs.
They solve different halves of the same problem and work best together. The coating stops heat and water arriving; the insulation stops what arrives from getting through.
No deposit. Payment due on completion. You approve the written proposal online before we order a thing.
