Hi All,
My builder has recently finished the complete house renovation with around 10m long flat 'cold deck' roof on each side of the house extension and didn't put any abuttment ventilation on the sides touching the wall. Roof is GRP. He had only put the ventilation holes on the soffit.
All work is finished including inside ceiling plastering and we are living there oblivious to the fact that cold deck roof is not fully ventilated.
Now, builder is coming back after persuasion to create ventilation on the flat roof and suggesting to put the mushroom vents like below above the joists so it can cover ventilation on each side. He's going to stick these mushrooms on the GRP roof with some sort of special silicone and edges to be sealed with lead based silicone.
There are going to be nearly 45-50 such mushroom vents to go on the roof and I am concerned that if any of these silicone gives up in next few months / years due to heat , cold and rain (extereme weather in UK), water will start going though those gaps and will start showing up damages on the inside of the ceiling way later in the stage. By that time, builder would be paid and I am sure he won't come back.
Can you please suggest which mushroom vents are more suitable for the GRP roof? Of any particular way such mushroom vents to be stick to the GRP roof so they last as long as the GRP roof lasts.
Builder suggesting this mushroom vent
My builder has recently finished the complete house renovation with around 10m long flat 'cold deck' roof on each side of the house extension and didn't put any abuttment ventilation on the sides touching the wall. Roof is GRP. He had only put the ventilation holes on the soffit.
All work is finished including inside ceiling plastering and we are living there oblivious to the fact that cold deck roof is not fully ventilated.
Now, builder is coming back after persuasion to create ventilation on the flat roof and suggesting to put the mushroom vents like below above the joists so it can cover ventilation on each side. He's going to stick these mushrooms on the GRP roof with some sort of special silicone and edges to be sealed with lead based silicone.
There are going to be nearly 45-50 such mushroom vents to go on the roof and I am concerned that if any of these silicone gives up in next few months / years due to heat , cold and rain (extereme weather in UK), water will start going though those gaps and will start showing up damages on the inside of the ceiling way later in the stage. By that time, builder would be paid and I am sure he won't come back.
Can you please suggest which mushroom vents are more suitable for the GRP roof? Of any particular way such mushroom vents to be stick to the GRP roof so they last as long as the GRP roof lasts.
Builder suggesting this mushroom vent
