re-roofing EPDM

[doughere]

I'm looking to replace my EPDM roof (with new EPDM material). I have often heard one of the steps is to replace the roof decking. Is this necessary if existing material can be removed and decking is in good condition.

Anyone do this??

Thanks,
Doug

[hypoxia]

Dougrainer is the best source here. I have done two, the first required new decking. On the next one I was fortunate in that the remaining adhesive was easily scraped off leaving a smooth surface. That isn't something you can count on.

I am curious, why are you replacing it?

[RAS43]

doughere wrote:
Removing is not an option; I guess I will have to just skim with some Lauan plywood.Doug

Last year we had a new EPDM roof installed due to an incident with a tree limb and that is exactly what the shop did- installed 1/8" luan over the plywood decking which was rough due to removing the old roof. Looks great and is smooth.

[dougrainer]

doughere wrote:

TucsonJim wrote:

dougrainer wrote:
1. Even if you get the OLD EPDM pulled off, you will have old glue and splinters of decking making an uneven surface. That means when you roll out the NEW EPDM and glue it down, you will have all those imperfections showing thru and will look real bad.
2. Once you pull the old EPDM, the old glue remnants will not allow the new EPDM to adhere correctly.
3. Without new smooth decking, attempting to clean off or keep dirt and debris from sticking to the old deck/glue will be a losing attempt.
4. This is advice from a professional that has done hundreds of EPDM roofs. Not some Rv'er that thinks they know what and how to do:B Doug

Doug - Would it be about the same labor to thoroughly sand the existing decking? Or would it be easier to just replace it?

My problem is not actually replacing the decking, but that the existing decking is part of a sandwich roof. Roof is interior finished plywood / foam core / exterior plywood all bonded together. Removing is not an option; I guess I will have to just skim with some Lauan plywood.

Doug

When we have your type roof, you then deck over the existing and wood glue the new decking and use countersunk screws to secure the new decking over the old. Doug

[doughere]

TucsonJim wrote:

dougrainer wrote:
1. Even if you get the OLD EPDM pulled off, you will have old glue and splinters of decking making an uneven surface. That means when you roll out the NEW EPDM and glue it down, you will have all those imperfections showing thru and will look real bad.
2. Once you pull the old EPDM, the old glue remnants will not allow the new EPDM to adhere correctly.
3. Without new smooth decking, attempting to clean off or keep dirt and debris from sticking to the old deck/glue will be a losing attempt.
4. This is advice from a professional that has done hundreds of EPDM roofs. Not some Rv'er that thinks they know what and how to do:B Doug

Doug - Would it be about the same labor to thoroughly sand the existing decking? Or would it be easier to just replace it?

My problem is not actually replacing the decking, but that the existing decking is part of a sandwich roof. Roof is interior finished plywood / foam core / exterior plywood all bonded together. Removing is not an option; I guess I will have to just skim with some Lauan plywood.

Doug

[dougrainer]

TucsonJim wrote:

dougrainer wrote:
1. Even if you get the OLD EPDM pulled off, you will have old glue and splinters of decking making an uneven surface. That means when you roll out the NEW EPDM and glue it down, you will have all those imperfections showing thru and will look real bad.
2. Once you pull the old EPDM, the old glue remnants will not allow the new EPDM to adhere correctly.
3. Without new smooth decking, attempting to clean off or keep dirt and debris from sticking to the old deck/glue will be a losing attempt.
4. This is advice from a professional that has done hundreds of EPDM roofs. Not some Rv'er that thinks they know what and how to do:B Doug

Doug - Would it be about the same labor to thoroughly sand the existing decking? Or would it be easier to just replace it?

Yes, you could sand(VERY dirty and messy). What do you think that old adhesive will do to any sanding disc or paper? We do not do that. We replace or overlay the OLD decking. I would think it would be MORE labor to attempt to sand than just glue and screw new decking on. Doug

[TucsonJim]

dougrainer wrote:
1. Even if you get the OLD EPDM pulled off, you will have old glue and splinters of decking making an uneven surface. That means when you roll out the NEW EPDM and glue it down, you will have all those imperfections showing thru and will look real bad.
2. Once you pull the old EPDM, the old glue remnants will not allow the new EPDM to adhere correctly.
3. Without new smooth decking, attempting to clean off or keep dirt and debris from sticking to the old deck/glue will be a losing attempt.
4. This is advice from a professional that has done hundreds of EPDM roofs. Not some Rv'er that thinks they know what and how to do:B Doug

Doug - Would it be about the same labor to thoroughly sand the existing decking? Or would it be easier to just replace it?

[RVcircus]

We did our roof last summer due to water damage, but I wouldn't replace any decking unless there's damage to it.

[dougrainer]

1. Even if you get the OLD EPDM pulled off, you will have old glue and splinters of decking making an uneven surface. That means when you roll out the NEW EPDM and glue it down, you will have all those imperfections showing thru and will look real bad.
2. Once you pull the old EPDM, the old glue remnants will not allow the new EPDM to adhere correctly.
3. Without new smooth decking, attempting to clean off or keep dirt and debris from sticking to the old deck/glue will be a losing attempt.
4. This is advice from a professional that has done hundreds of EPDM roofs. Not some Rv'er that thinks they know what and how to do:B Doug

[harold1946]

As long as the substrate is in good condition it will be fine. I would also suggest reroofing with TPO. Its a much better material and the top layer does not sluff of like EPDM.

[Explorer1016]

I have not performed this repair but I have studied video's on the subject for the day when I will need to do this. Go to Dicor's website. They have some very good videos on this and do a walk through for you.

the only reason's you would need to replace the decking substrate is if there are bad spots, then, replace those areas, other reasons, if you want to add insulation, change/repair wiring in the ceiling area etc. This will be an easier access than removing the interior ceiling panels since you assumingly would already have the EDPM roofing removed.

This will be a great subject for the forum. I hope you post pictures along the way and do a step by step review for us. Good luck.

[hypoxia]

Unless you have rotted decking you can go over the original deck.