Most good quality sole leather is attached to the shoe’s upper by the traditional goodyear welted method of construction. Classic leather soled Sebago shoes are constructed using Sebago’s own patented version of this method. Such soles will give some water resistance, but when worn in wet conditions water will eventually penetrate through the welt and welt seams and through the soles, especially as they grow thin with wear. Welted rubber soles will offer a great deal more water resistance.
Uppers made of textile materials such as denim, hessian and canvas will leak when wetted. Leather uppers will have some water resistance but water can penetrate rapidly through seams in the uppers as well as decorative stitching and perforations. Water will find its way along the thread. However and this can be prevented with a regular application of a wax polish which will block the water penetration whilst the shoe will remain breathable.
Cementing the sole to the upper is a much cheaper method of shoe construction and is used for all sorts of types of footwear. Water will penetrate through the upper/sole junction and the sole if it is leather.
Moulded–on rubber or plastic soles will almost certainly be more waterproof than leather but leakage can still occur at the point where the sole is bonded to the upper.
Veldtschoen shoes, sometimes known as the double-upper veldt, is used in some types of shoe which come with a water proof guarantee.
Machine-sewn, otherwise known as Blakey shoes, have the sole sewn on whereby the stitching goes right through both the sole and the insole. Even if the sole attaching is channelled and the channel closed to cover the stitching, water will rapidly find its way through to the inside of the shoe via the sole stitching.
Moccasin shoes are also machine sewn and will let water in the same way. The typical apron seam on the vamp of the upper also allows penetration of water. Many moccasin styles have quite a rugged look but in spite of this they are not intended for rugged use and will certainly not keep water out. However they do lend themselves remarkably well to deck shoes where the shoe is designed specifically both to let in, and crucially, also let out water, hence the popularity of the Sebago Dockside.
Sebago use their unique stitched welt construction method to attach the leather sole to their beef roll loafer.