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Mansarde - Ventilation MaximumFrequently Asked Questions" class="rev-slidebg" data-no-retina> Frequently Asked Questions

Technical questions

No, The ventilators will draw from the gable vents and exchange the air near the top of the attic, but it will not draw from the eaves due to lack of air intake. You will need to install our VMAXAT-1 or VMAXAT-2 so that the ventilator may draw in fresh air at the eaves while picking up the moisture on its’ way up and out the ventilator. You will also have to close the gable ends as to not short circuit the ventilator.

No, you must always use the same model of ventilator, otherwise the stronger ventilator will draw from the weakest, therefore short circuiting the system. This is why we recommend that you block off or remove all other vents on the roof.

The roof ventilator model #401 will have a stronger drawing power than that of the turbines, which means it will be short circuited by the ones left on. I would recommend that you either replace them by our model #301 or by the replacement head, model #401. All ventilators that are used to ventilate the same attic space should be identical units of equal drawing power.

The Maximum ventilator will draw from these openings being closer and less restrictive, rather than from the soffits.

You will install the roof ventilators no closer than 3 ft. from the vertical wall. Make sure that it cannot get covered by snow accumulation near the wall.

The roof ventilators should be no further than 20 ft. apart from one another. Each unit should be positioned so as to ventilate an equal portion of the roof. If you have one ventilator, it should be placed in the centre, if you have two units, each unit should be positioned at ¼ distance from each end of the roof. (See installation documents for more details).

The Maximum ventilators are activated by the wind, and knowing that the wind directions changes during the year, we want this wind to pass threw the louvers from all directions that it may come. This way, the ventilator will work efficiently year long.

We recommend that you install two ventilators, one on each side of the chimney no closer than 4 ft. from the chimney. You can use the same model (it will only replace the air faster) or you can use our model #303. Make sure that the chimney is higher than our ventilator so that the smoke doesn’t flow threw the ventilators. This could cause the smoke to enter the attic space when wind velocity is nil, especially night-time.

Distance and measurements

Problems solving

The roof ventilator will work if the wind hits at it, but there will be draw backs that you must consider:

a) If for instant you are installing our model #301, you know that it can ventilate 1200 sq. ft., but if you position it midway up one side of the roof, it will only ventilate the bottom of that side instead of the entire attic space;

b) The ventilator will be vulnerable to snow accumulations which might lead to infiltration if it is totally or partially buried under snow.

Yes, you can have some problems since our ventilators have a very strong drawing power. The vapour barrier is very important to prevent humidity and hot air from entering the attic space easily especially if there is no air intake. You can easily fall in negative pressure and thus increase your condensation problem. Before you install a ventilator you must find a way to open the soffits or add some other form of air intake to your building (see last two sections of the product sub- section on our web site). If you cannot add a vapour barrier, you must at least add additional insulation to your attic space. The addition of ventilation on the roof must be done progressively with our least efficient model the 302.

Yes, you can install the roof ventilator on a metal roof two ways, off to the side with our regular flashing that comes standard with the ventilator, or you can install it directly onto the peak with a ridge flashing that we can custom build to the slope.

The Building Code states that you should ventilate the insulated ceiling area of a building, so in this case you would only need one ventilator. However, we recommend that if this is a duplex where you have two families, moisture levels will be higher, so it would be more efficient having two.

No, we recommend that you install the model #302 and space them evenly over the roof to allow for an efficient air exchange. You will need to ventilate 1/150 per code due to the small attic space, which will require you to install five.

Due to the thickness of the steel (24 gauge steel), it will not bend to the shape of a warp or uneven deck. So, we strongly recommend that all our products be installed and perfectly sealed with a good quality caulking or sealant, otherwise we cannot guarantee water or snow infiltrations coming from under the base. As for the tar melting down onto the shingles, quality is the most obvious issue. Having been roofing contractors ourselves, we have never experienced this problem. As well, this is also strongly recommended by the Master Roofing Association.

Installation issues

General questions

We recommend that you install two roof ventilators, one on each side of the chimney no closer than 4 ft. from the chimney. You can use the same model (it will only replace the air faster) or you can use our model #303. Make sure that the chimney is higher than our ventilator so that the smoke doesn’t flow threw the roof ventilators. This could cause the smoke to enter the attic space when wind velocity is nil, especially night-time.

We have never encountered this problem, and we believe the reason is because there is to much air movement within the ventilator. Have you ever noticed that insects are never flying around breezy or windy areas?

No, if the house in question is well insulated per standards, has a proper vapour barrier and the soffits are unobstructed and balanced or exceeds the opening of the exhaust vents, this shall never be an issue.

Architects

Are you looking for detailed specifications of exhaust fans and flaps for architects and construction professionals?

DIMENSIONS ET CARACTÉRISTIQUES – SOFFITE ANTI-RAFALE MURAL