John Jeffkins

STUDIOT thanks for your interest. I am in South East England. The door warps along its length, it bows in, which is counter intuitive. The door was fitted by a professional, with three100mm hinges, fixed securely to a solid frame. I mentioned the overhang above to rule out rainwater and in any case it hasn't rained for the past month. I chose an engineered door as I was advised this was the best option, with an oak finish for toughness. We have to paint the door dark grey or black because of planning restrictions. The door construction seems to be a 40mm thick particle board core with 2mm of veneer front and back and 20mm of oak to the perimeter. Although we have had some quite sunny afternoons, the highest temperature has only been in the high twentys. The Frame was hand made by others. I'm not really in any doubt that the heat from the sun is causing the door to warp as a result of some kind of differential expansion. The problem is that the supplier is blaming the paint system, suggesting that its UV causing the bow. I need to debunk this argument and get a refund so I can buy another door, probably a solid timber one. John

Sensei I dont want an investigation. I asked for help debunking my door suppliers argument that UV was the cause. Others, more helpful than yourself, have pointed out that its Infrared radiation causing the door to heat up. As for what I want, well a refund, so I can buy a better constructed door.

Im sure you are right, the door is veneered inside and out and obviously the outside is getting much warmer. The problem is that the door manufacturer is blaming the paint manufacturer saying Wow, thats a negative response. Are you saying there are no engineered timber doors out there that can be painted grey and not warp in June sunshine.

I'm sure you are both right, the door is veneered inside and out and obviously the outside is getting much warmer. The problem is that the door manufacturer is blaming the paint manufacturer saying "it is the paint system that offers the UV protection for the door and it is the UV which is causing the thermal bow" This is clearly nonsense to me but the only way I can debunk there argument is with Scientific response, hence my plea for advice.

Evening. I am having a problem with a new engineered timber front door which has a man made core and oak veneer surface. The door is painted in three coats with quality paint and has a dark grey finish. The door faces east and is well protected from the rain. Over the past few weeks on sunny afternoons, the door warps approximately 6mm and then returns to its straight shape sometime the next day. The door supplier says this is because the paint system isn't stopping the UV radiation and are refusing to do anything. Surely no paint can stop the warming effect of the sun and as the paint is dark grey presumably it is actually increasing the heating effect. Can anyone talk me through the science so I can go back to the door manufacturer and argue my case. Any advice would be appreciated as the door was quite expensive. regards John