Water in an Avan

Most A’vans suffer at times from internal fogging of windows or condensation on internal aluminium surfaces, but some owners have found damp in the bottom corners of cupboards or water marks on the lower surfaces of walls. What is the cause, and how can it be fixed?

If water gathers in a van it should be rectified promptly as a wet van quickly deteriorates.

There are a limited number of sources of moisture:

 Water from the road which can enter when splashing through deep water.

 Internal leaks, such as from a leaky container or perhaps from leaking piping. When our van was new a number of pipe joints leaked so we dismantled the push-in joints (by sliding the collar along to loosen the claws gripping the pipe), cut the pipe square, and ensured the outer surface of the pipe was unmarked before remaking the joint. As a precaution we fitted John Guest collet locking clips model CM1815 to the joints.

 Internal condensation can occur if it is cold outside while the interior air is humid. Moisture given off during cooking, boiling a kettle, washing up and from the occupants remaining inside as the outside temperature falls condenses on the coldest surfaces, such as windows, exposed aluminium and in remote unheated corners. It is particularly noticeable on cold frosty mornings if the windows were closed overnight to conserve heat and may soon evaporate from visible surfaces as the day warms up, but it lingers on in unventilated cupboards. Condensation can be controlled by minimising steam from the kitchen and by maintaining adequate ventilation by keeping one or two of the top vents open at all times in camp.

David Hall 3130 June 2010

 Rainwater entered our Avan at the rear corners where the side walls meet the roof. We found that rain from the top of the rear roof panel ran down to the black sealing strip then across to the low side, over the side and down the aluminium edge of the roof to the rear corner, where it flooded in behind the small triangular flashing. We attached triangular Colorbond flashings inside the aluminium roof edge with short pop rivets. They are about 10cm wide and 10cm high, hanging outside the standard flashing and carefully aligned to avoid interference as the roof is closed. The front edge of the flashing has a 6mm wide return folded in at 45 deg to intercept water running down the edge of the roof, and there is a 6mm return of 90 deg at the back edge. We glued 10mm water resisting foam to the inside of the flashing to form a seal against the wall when it is up. The photographs also show the drip notch we cut in the underside of the aluminium edge to reduce the amount of water reaching the rear corner. This treatment proved effective, so we also flashed the front corners as a precaution.

David Hall 3130 June 2010  A little rainwater also seeped in around the side hatches and this was overcome by gluing a strip of 2mm thick neoprene around the inner faces of the hatch covers to increase the pressure on the existing seal.

 We found that water entered the fibreglass boot of our Cruiseliner and in a test with a watering can there was a shower coming through the piano hinge. We removed the piano hinge and wrapped 2mm neoprene sheet around it before refitting it with sealant. Our boot is now dry.

David Hall 3130 June 2010