first off you haven't stated your problem is your door leaking is it drafty or is the seal damaged.if the door is five or more years old you might struggle to get the gasket to match things change rapidly in the double glazing industry.there are a few types of gasket some are put in by hand during fabrication in the factory others are fitted at the time when profile is extruded without complicating thing you need find how long the door has been fitted or try prising the gasket out with a flat head screwdriver taking care not to damage it. and then if it starts coming out fairly easily make note of which way round the small flap is if it has one and then take it with to your local double glazing company to see if they use anything similar you might have to do a bit of leg work but they should advise you if that particular door system is obsolete or not without anymore information that's the best i can advise
mark, January 2011
