If you are venting through the roof, the blowback vent grills are irrelevant to that.

Thanks! What's confusing is the the installation guides for both GE (CR top rated OTR) and Whirlpool microwaves say that a depth more than 12-13" won't work, and the guides don't make a distinction between recirculating and outside venting. Unfortunately, the customer service people on the 800 lines are trained to read only from the installation guide.

On the old GE OTR that we have currently installed, these vents are also top front facing you, but on all the new models from every manufacturer they face the ceiling.

I'm not a professional, but I've installed several OTR microwaves. I think you could add blocking to push out any brand of microwave to the desired depth. For example, add horizontal 2x4s to the back wall, attached to studs, where the microwave brackets would go and at the bottom of the microwave. Then mount the microwave to these. This would add 1.5" to the depth. Cover the exposed bottom blocking with an aluminum or steel angle or plate, painted.

That's a good idea. Because we have a narrow kitchen, I would like to avoid having the microwave stick out even more than the 15 1/2" depth (including cabinet doors). It appears that the vents are only for recirculate, but GE and Whirlpool customer service are unable to confirm that.

Another thing to check is the door swing. I just looked at my current Whirlpool. The hinge side projects almost 3/4" from the left side of the unit when opening, beyond the 30" width. Check that yours will open if it's recessed more deeply than usual between the cabinets. The Whirlpool's doors are about 1.75" thick and would need to sit fully in front of adjacent door faces to open, so you'd need at least 2" projection.

Photo of microwave door projection. The door thickness is just about the same depth as the top vent. If you recessed the top vent, the door wouldn't have space to open. Different models may have a better hinge setup.

Kitchen · More Info

Thanks for posting the picture! I'll definitely need to check out the doors. If I remember correctly, maybe the GE doesn't need extra room around the hinge to open.

You need to cover that exposed wood at the rear with metal.

Sorry, I don't have a picture, but I did the exact same thing as dunstonstl a couple of weeks ago with a GE microwave. However, I sprayed the 2x4s with high temperature resistant paint before installing them

High temperature paint over wood won't satisfy the fire code. Or your insurance company. Anyone that does this needs a metal spacer there. No combustible wood over a cooking zone!

It looks like the 2x4 method is causing some concern, however, I wasn't able to find any specific code guidelines or info pertaining to this in the microwave instruction manual. For comparison, the IKEA Nyttig filler piece is made of particle board and has a thin stainless strip that only covers the bottom edge. Is particle board any less combustible than a 2x4? When you say cover the exposed wood at the rear, do you mean cover by something other than the metal of the microwave, and are you referring to the front facing side as well as the bottom? While I agree, you wouldn't want a 2x4 exposed at the bottom for aesthetic reasons - which is why I used a filler piece for the cabinetry to cover that - I'm not sure I follow the logic of why it has to be metal.. when the other two sides perpendicular to the microwave are wood/cabinet edges also. Once the back splash is up and the cabinetry cover panels are covering the IKEA melamine frames and all of the seams are caulked, how is that any more dangerous than say a wood/cabinet grade range hood for instance? Just curious if anyone could provide further clarity or resources specifically on where to buy or how to build the bump-out piece. Thanks!

Fire codes require a clearance of 30" above a cooking surface to a combustible surface. A separate metal angled piece covering the area will suffice to protect it. A laminate covered filler piece will not. Wood hoods are designed so that a metal liner covers the actual range area, or they are mounted at 30"-36" above the cooking surface.

Alright, I think I gotchya. The only reason I went with 2x4's to begin with is b/c IKEA seems to be continuously out of stock on the Nyttig piece. Probably can't beat their $10 price for the thin metal strip already fit to the correct dimensions. I'll swap it out if I can ever find it in stock or just use some similar sheet metal at a home improvement store. I still don't see the difference though, considering the wood on the adjacent wall cabinets is actually closer to the cooking elements than the back wall behind the microwave.. oh well, when it comes to IKEA, what's one more step..

so does the metal back to the wall or show up front for design purposes. They sell you the part and no instructions. SMH I have already built the cabinet. Perhaps I should take the new microwave from the box and line it all up for a visual? A bit frustrating the first time around.....

My Samsung microwave still leaves a steamy haze on the cabinet doors when cooking even though it is vented through the wall to the exterior. I believe the exhaust fan is to remove the heat steam from stove top pots and cooking.

I know this is an old thread, but has anyone found a microwave that actually works with IKEA depth cabinets, without any blocking/modifications? On the IKEA website, the microwaves they sell look to be almost flush with cabinets, and don't look like they have spacers/blocking behind them (see photo below) but they also don't get great reviews.

Look at Ikea appliances. Those should fit.

Those photos appear to show 12" deep cabinets.

Note that the IKEA micro/hood spacer does not actually meet the fire resistance requirements of the Ontario Building Code (OBC), The OBC wants at least 1/4" of fire rated insulation (asbestos) covered by at least 1/8" of steel for anything horizontal in that area. The IKEA space block, while a wonderful work of art (looks fantastic!) just consists of about 1mm of stainless steel wrapped around the underside of a flammable particle board block. For something over a gas range, it does not meet the OBC requirements.

I had the same situation and I got a metal track from home depot and a can off stove white paint I cut the two pieces off metal and paint the bottom one white just for the look. All for under 10U$

GE makes a 3” bump out bracket for 15” cabinets. It isn’t cheap but it solved my problem.

Has anyone who bumped out the microwave to fit with Ikea cabinets felt like it was sticking too far out over their stove? Has this bothered anyone?

This thread is very interesting and exactly what I was looking for...my new kitchen has the stove in a corner wall that is very frustrating and I'm trying to decide on my options but am concerned my Whirlpool micro won't open if I install it without doing something. All my 15" depth cabs are here and I'm not sure I shouldn't go back to 12's...too bad the IKEA assistant didn't warn us about the layout and issues with those cabinets - we live 4 hours away and right now I don't know when we'll have all the parts to our cabinets due to COVID. Thanks for sharing.

The microwave doors need a few inches on the left side to open. You can not mount them with the left side against the side wall. And for that matter, you should not mount them against a right side wall either; they all seem to be left hinged.

I have a GE OTR microwave. I had to buy a pop/set out piece. They aren’t cheap for a piece of sheet metal, but work perfectly. I am sure that Whirlpool offers something similar.

Planning to do IKEA kitchen remodel soon, and ran into this situation as I was planning the kitchen layout. Found the following IKEA parts to solve this. Thought others would find it useful.

Top spacer for flat-bottom cabinets to route the microwave cable

804.904.72 - NYTTIG Filler piece for over the range microwave

Back spacer (this has stainless steel underside to meet building codes)

102.822.40 - NYTTIG Filler piece for microwave/hood

This would just push the microwave to the front by 2 inches.

Hello, newbie girl here needing some help with the ikea microwave install. Hoping someone can answer some dumb questions...

A. I know that I need to use the Nyttig spacer but I’m not clear on how this works with the mounting bracket. Wanted to confirm: I should attach the nyttig spacer to the wall stud (using super long screws). Next, I attach the mounting bracket to the nyttig spacer. Is that correct?

B. The instructions say to leave a 1/4” gap, my understanding is that this refers to the comments above where the microwave needs to stick out from the cabinet for venting and door hinge allowance - is that correct? There is no other 1:4” gap required anywhere else, correct? (The instruction pictures almost make it seem like a 1/4” clearance is required between the top of the microwave and bottom of the microwave cabinet. Which doesn’t make sense to me...but I wanted to be sure.)

Any info you might have is much appreciated.

JP, I have the exact same questions as you with a microwave I just bought (they sound like they're the same or very similar), did you figure out the answer to your questions? :P

Bought an ikea microwave w the ikea kitchen. Installed with ikea filler pieces, door still doesn’t have clearance to open. Ikea had no answers. About to do a 2x4, but wondering if anyone had just doubled up on the nyttig pieces? The piece behind the microwave in their pictures definitely more than 3/4 like the nyttig…but what is it!? And how do I get one?

So happy I found this page. We recently redid our kitchen last year and didn't get the microwave above the range until now. It wasn't until I read the instructions about adding fillers and etc for anything >13. I scoured youtube and found nothing. I was hesitant to continue moving forward with the installation. It wasn't until I decided to search the web instead of vids and it worked. I know now I need to get two 2x4's for the back...but I'm uncertain what I need for the top for the flat bottom sektion cabinet. I was hoping for some info about it here but no luck. I was going to find some piece of wood about 3/4 thick about 30" wide and hope for the best.

Looks like IKEA discontinued the back filler piece…