Replacing dome skylight with EPDM

[Sulphur1]

I'm down in Australia and replacing a Kitchen area dome (too hot) with a square of EPDM roof material. Dicor EPDM adhesive directions state that it is not meant for rubber to rubber. After first gluing the rubber sheet to the replacement ply do I then use the adhesive under the top (original roof) EPDM overlap or use Dicor Lap Sealant? As a final seal I am intending to also tape the joins with Eternabond.
Appreciate your experiences and comment.

[JRTJH]

Rather than cover the skylight (or is it a 14"x14" roof vent) ??? Anyway, rather than covering it and then "missing out on the light when it's not too hot", why not just insert a "foam pillow" on the inside ??? We've done that for years in our bedroom roof vent and in the winter, it's as warm as the rest of the roof, in summer it's as cool as the rest of the roof. The pillows cost about $25-30 for two at Amazon and when you "wish you had the light" it stores anywhere you toss it. https://www.amazon.com/Insulator-Uni...s%2C122&sr=8-5

[Sulphur1]

It's gone!

[Sulphur1]

Sorry, John I haven't mentioned that the length has been reduced 3 feet.

[JRTJH]

The length of the skylight has been reduced 3' ????

I don't think I've ever seen a skylight that large in any Keystone product installed by Keystone. Is this some type of aftermarket modification ???

Anyway, all those "vent pillows" are is a piece of 3" foam covered by a "fuzzy fabric on all sides except one. That side is covered by aluminized "bubble wrap" that's commonly used in the building trade as a "heat reflector/insulation enhancer"...

You might consider having an upholsterer make you one to fit your "custom sized skylight".

If the existing roof is not leaking, I'd be very reluctant to remove the skylight dome and build an "insert for the roof decking" than attempt to cover over that with a patch....

[sourdough]

OP are you talking about a normal 14x14 roof vent/skylight or something else? My trailer has a skylight that's about 3' long and maybe 14" wide but it has a sliding cover inside so it can be closed (it's never been opened except during the walk through). Are you referring to something like that?

[Sulphur1]

No, taken 3 Ft off the end of the Cougar High Country. Re rearranged rear kitchen, length of slide out, added rhs entry door and tanks,etc.
Roof where dome skylight was is now over kitchen cupboards. Have replaced ply roofing and now ready to cover with EPDM rubber roof.
Why I'm looking for advice to do it right. Cheers

[Sulphur1]

No advice on how to seal the lap?

[sourdough]

If others are like me, I'm totally confused about what you've done, what you're going to do and what you need. Can you provide pics?

[rhagfo]

Originally Posted by Sulphur1

No, taken 3 Ft off the end of the Cougar High Country. Re rearranged rear kitchen, length of slide out, added rhs entry door and tanks,etc.
Roof where dome skylight was is now over kitchen cupboards. Have replaced ply roofing and now ready to cover with EPDM rubber roof.
Why I'm looking for advice to do it right. Cheers

Originally Posted by sourdough

If others are like me, I'm totally confused about what you've done, what you're going to do and what you need. Can you provide pics?

Well to me sounds like a major remodel to his 5th wheel, lopped 3' off the back end and now either a 3'x14" skylight, or a 14X14 vent opening is above the new kitchen cabinets.

I think new EPDM roofing over the patch, then seal the seam with Eternabond tape. Very ambitious project!
I would like to know what brought on the project.

[sourdough]

Originally Posted by rhagfo

Well to me sounds like a major remodel to his 5th wheel, lopped 3' off the back end and now either a 3'x14" skylight, or a 14X14 vent opening is above the new kitchen cabinets.

I think new EPDM roofing over the patch, then seal the seam with Eternabond tape. Very ambitious project!
I would like to know what brought on the project.

Yes, that's what it "sounds" like but it also sounds WAY ambitious and it's why I asked for details/pics. With that extent of renovation/modification just guessing doesn't do a lot of good.

[Sulphur1]

Yes, that's what I've almost finished, roof next to be done.
Originally purchased a High Country 299RKS but did not know you measure length on the inside in the US. Hence a lot longer than suited our needs in terms of weight, manuverability and storage. Otherwise been fine to use.
' Been a fairly easy job too do, just time consuming and many items to think of at once.

[sourdough]

If I am understanding where you are, you have covered the original skylight at the roof level with plywood and are wanting to cover it up with EPDM? Is the rest of the roof covered in EPDM as well?

I would cover the open plywood with the EPDM using the proper adhesive. I would not seal the gaps with Dicor but instead cover them well with Eternabond then seal the edges of the Eternabond with the Dicor sealant.

[Sulphur1]

Yes, that is right Sourdough and thanks for the reply. I've ordered the Dicor adhesive to cover the ply and will fold back the old roof to allow for overlap. Bit like sealing an envelope. I would normally seal under the overlap with the same adhesive and as a final tape withe Enerbond to finish off. However, the Dicor adhesive instructions say it won't glue rubber to rubber - hence my question.
I've been also thinking of sealing under the laps with Dicor sealant rather on top - this is the way roofers would do it on a house. Cheers Jon

[sourdough]

Originally Posted by Sulphur1

Yes, that is right Sourdough and thanks for the reply. I've ordered the Dicor adhesive to cover the ply and will fold back the old roof to allow for overlap. Bit like sealing an envelope. I would normally seal under the overlap with the same adhesive and as a final tape withe Enerbond to finish off. However, the Dicor adhesive instructions say it won't glue rubber to rubber - hence my question.
I've been also thinking of sealing under the laps with Dicor sealant rather on top - this is the way roofers would do it on a house. Cheers Jon

Dicor is not like the sealant roofers use. Those are sealer/adhesives and Dicor isn't. If you are using an adhesive already for the EPDM use it for the laps as well. The Dicor will be best suited for covering the seams on the top after you apply the Eternabond.

[Sulphur1]

Thanks, try on a scrap when dicor comes in.

[rlh1957]

If the sealed skylight isn’t leaking, leave it alone.
Use a piece of foam insulation with Reflectix on the up side and cover inside with your choice.

Messing with a roof light or vent opening is ambitious and could have leak issues in tge future.

[sourdough]

Originally Posted by rlh1957

If the sealed skylight isn’t leaking, leave it alone.
Use a piece of foam insulation with Reflectix on the up side and cover inside with your choice.

Messing with a roof light or vent opening is ambitious and could have leak issues in tge future.

OP mentioned in post #7 and later that the hole was already covered with plywood topside and he's researching the method to cover/seal it.

[rlh1957]

Originally Posted by sourdough

OP mentioned in post #7 and later that the hole was already covered with plywood topside and he's researching the method to cover/seal it.

Thanks. Not reading all the details before answering.