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Cold drafts under kitchen cabinets or dishwasher are most likely caused by holes around plumbing inserts, which create a direct route into the house from outside. Old houses may have unsealed and disused vents, which allow cold air in. A lack of wall or floor insulation can also create cold drafts.
Cold drafts in and around kitchen cabinets can be a pain, especially during the winter months when the chilly air makes your HVAC systems work extra hard to keep your kitchen warm. It could be a slight chill that you only experience when you open your cabinets or it could be more severe, spreading to surrounding areas.
If you are experiencing cold drafts under your kitchen cabinets, here is a guide to help you find the source of the draft and also help you decide on the best course of action to fix the problem.
Sources of Cold Draft Under Cabinets/Dishwasher?
The most important thing to note is that the only way cold air can infiltrate the cabinets and your heated kitchen is from the outdoors. Thus, you’d have to search for anything that can allow outside air to enter your home.
Cold drafts could be caused by major issues, like poor external insulation, or minor defects, like gaps around plumbing fixtures.
If you notice minor issues like plumbing gaps that you can fix yourself, you should start there. However, if you still notice the penetration of cold air after that, then you can proceed to address insulation-related problems.
Plumbing Holes Badly Sealed
You should examine beneath your sink and other connections for holes. Check to be sure that all plumbing fixtures are tightly connected without any loose room. Gaps around fixtures such as dishwashers, drainpipes, gas fireplaces, etc., are very common. Anywhere you have an appliance or object directly connected to the outside, cold drafts are something you have to address.
If you find holes or gaps between your pipe connections and drywall, then you’d have to seal them so that they cease to act as an energy sink (allowing unconditioned air in and conditioned air out).
If there are pipes that enter your kitchen from an underfloor location like the basement, you still have to ensure that there is no space around the entry holes, particularly with an unfinished, and therefore unconditioned, basement.
The issue might even be because of loosely fitted dishwasher pipes. In this case, the holes might not be glaring, but they could still be big enough to allow external air into your house.
So, you’d have to check all your pipes and plumbing connections for gaps or holes. Even if you notice a tiny hole while searching, cover it up so that it doesn’t expand later. Also, check for holes around electrical connections and seal them if you find any.
Poor Insulation Behind Cabinets or Dishwasher
Oftentimes, cabinets are installed directly on exterior walls. In situations where the exterior walls have little or no insulation, adding loose-fill insulation like cellulose or spray foam can help to limit the passage of air into your home. This would serve as a protective barrier that prevents external air from entering your house.
A more extensive procedure involves installing insulation panels on external walls.
If the chill is coming from your dishwasher cabinet, you would have to remove the dishwasher in order to analyze the cabinet walls. In case the cupboard is installed directly to the wall, check for holes, especially on the floor to wall joints and the points where two walls meet. If you notice gaps, fill them with expanding foam.
If the cabinet is attached to a back panel, you might have to remove it to check for holes in the wall behind.
Insufficient Floor Insulation By Cabinets/Dishwasher
Another thing that might be allowing drafts into your home is ineffective floor insulation. This is more prominent in houses with crawl spaces and buildings constructed on piers. Even if your kitchen isn’t built above a crawl space or basement, as long as your kitchen is located on the ground floor, drafts can enter your home from the underfloor area.
Solid floors aren’t likely to have gaps, but if the floor in your kitchen is constructed with suspended timber, then you’d probably have to insulate underneath the floor.
To prevent drafts from entering through the floorboards, you might have to lift the boards and then apply insulation between joists.
Floorboards often expand and contract with time (which is one of the causes of squeaky floors), so if you use stripped floorboards in your kitchen, you should fill the gaps with a flexible gap filler so that they can withstand future movements.
Most built-in cabinets have gaps between the floor and the bottom of the cupboard. You can cover these gaps with canned foam or caulk.
Missing Sections of Insulation
Most old houses were not built in line with the present insulation standards. So, you’d notice that they were built with little attention to insulation. Even if the house has insulation, some parts might have worn out with age and this would reduce its functionality.
To fix this, you’d have to first determine the location of the gap in the insulation. It’s best to extend your efforts throughout the kitchen to ensure that you cover every source of air leaks.
Unless you want to hack out the entire drywall, which would be too much for a project of this scale, you cannot see the locations where you’re missing insulation. Instead, you can use a thermal imager (amazon link) to view areas without insulation. The device detects temperature differences, so it’s advised that you heat up the room if it’s hot outside and turn up the air conditioner if it’s cold outside so that the imager can easily detect all the areas with air leaks.
Disused Vents Behind Cabinetry
The issue of disused vents behind cabinetry is more prevalent in older homes or houses that have gone through a series of remodels.
Sometimes when houses undergo an upgrade, older vents might be abandoned and replaced with new systems. If this happens and the vent holes are not properly sealed, they could increase your energy bill significantly with how much air they allow into your space.
Thus, you need to investigate the area for vents that are no longer in use. It could be a range hood that’s no longer functional. In this case, the source should be obvious. It could also be an old microwave vent.
The best solution is to seal vents that aren’t connected to your HVAC system because even if they are not allowing outside air into your space, they could give pests like insects or even rodents access into your home.
Locate the Source
Step one in solving the cold draft problem is to identify the source of the cold draft. Thankfully, you do not need to have professional expertise to be able to discover the source of the draft.
To do this, you’d have to determine the exact spot where the draft is more intense. If you’ve been experiencing the cold draft for a while, then you probably know what area is the most frigid. After discovering the coldest location, you’d have to tenaciously search around your cabinets for gaps or holes.
However, if you cannot find the source of the draft yourself, it might be due to poor insulation and you might have to employ the services of a professional
Solving Insulation Issues
After you’ve discovered the source of the draft, the next step is to make targeted efforts to address the issue.
Installing Wall Insulation
If your cabinet is installed directly on a wall with poor insulation, the porous nature of the wall could allow frigid air to enter your kitchen.
Insulating an exterior wall is an intensive procedure. So, it is advised that you install external insulation when you are building or renovating your home. However, in this situation, you could install insulation only on the offending areas.
The process involves covering the wall with panels that are usually made of mineral wool, wood fibers, or polystyrene. The insulation panel is attached to the wall with an adhesive and then painted over.
This isn’t a DIY project. However, if you decide to do this yourself, you’d need to have at least intermediate knowledge or expertise in similar projects.
Alternatively, you can insulate your walls by applying blow-in cellulose or injection foam to the wall. This would create an air seal, thus preventing frigid air from penetrating your walls.
To fix missing insulation, you can cover large areas with insulation foam board or something like Reflectix (amazon link), and you can fill smaller spaces with foam-a-fill or expand-a-foam.
Whatever insulation you opt for, make sure it has an adequate R-value and is properly fire-rated for use in your kitchen.
Installing Floor Insulation
The first step to insulating your floor is determining your floor type. Most modern homes have their ground floors built with solid concrete and this type of floor isn’t really prone to air leaks.
A major drawback is that concrete floors are difficult and expensive to insulate. Since you cannot lift a concrete floor to apply insulation underneath, the process of insulating a solid floor involves layering it with rigid insulation. You can use materials like PIR boards, expandable polystyrene, or insulation slabs for this purpose.
Older homes mostly feature suspended timber floors which are usually susceptible to air leaks. If you have access to the underfloor area, you can easily insulate the floor from below. However, if you don’t, you might have to lift the floorboard, install the insulation and then put the floorboard back in place.
Insulating a suspended timber floor is easier if you have access to the underfloor area. The process usually involves installing rigid installation panels between the floor and joists.
Adding Cabinet Back Panels
The addition of cabinet back panels is a minor fix and might not completely get rid of the issue.
If your cabinet is installed directly on the wall, it’s a lot more vulnerable to drafts than it would be if it is installed on a backboard. The panel provides a layer of protection that limits the amount of air that penetrates into the cabinet.
This can also be done alongside floor or wall insulation.
Sealing Holes in Walls
Holes are the major cause of severe drafts. The size of the hole would control how much outside air penetrates your home.
Sealing Holes in Plumbing Fixtures
If you notice holes around your plumbing connections, you can tackle them by using spray foam, caulk, or a patching compound.
Spray foam is ideal for smaller gaps. When you are applying the spray foam, don’t spray too heavily in order to allow room for expansion.
If you are very conscious of appearance, spray foam might not be the best solution for you because it isn’t aesthetically pleasing.
Alternatively, you can apply caulk on holes that are less than 1/2” wide. For bigger holes, you’d have to fill the hole with steel wool and then apply caulk over it. Caulk can be painted over once it is dry, so you can, to an extent, “pretty” it up.
Another method is covering the area with a patching compound. If you would like to paint the surface, allow the patching compound to dry, and then apply joint compound. After the joint compound has set completely, you can proceed to paint the area.
Sealing Holes Caused by Unused vents
If you notice a vent that’s not connected to your heating and cooling system, it’s best to close it off because it could be doing your home a disservice.
To seal a vent, you would have to:
- Measure the width and length of the vent cover.
- Cut plywood sheeting to match the dimension of the vent cover.
- Remove the vent cover. You might be able to do this by pulling it out. However, if it is joined with screws, you’d need a screwdriver to take it off.
- Use metal tape (amazon link) to attach the wood to the vent.
- If the vent has screw holes, drill holes in the plywood to match those on the vent cover.
- Install the screw through the vent cover and plywood.
Alternatively, if the vents were installed on stucco walls you can seal it off by applying stucco over the vent.
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