Re: Firewall waterproofing dilemma - is their a solution at all?

Your problem Houseband is precisely the reason why I do not like valleys and roof-wall intersections in houses. These are often the cause of leaks.

A roof-wall intersection will have to be well sealed to prevent leaks. Rain falls on the wall, drips down on the roof and finds the smallest hole to leak through the wall beneath.

If I remember correctly, a firewall will have to be around 1 meter above the roof line. What I would do, if you have not yet done it, is to put GI above the top of the firewall, down to the roof and terminate well beyond the intersection of the roof. In this case, rain that falls on the wall is carried to the roof rather than falling on the intersection.

Re: Firewall waterproofing dilemma - is their a solution at all?

whew... that was fast...

thanks 2diy4 for the response. but your answer brought more questions to my simple domesticated mind... 🙂

1. what exactly is a roof-wall intersection? is this a neighbor's roof jutting against my firewall? I asked because there are really no structures attached to my firewall. or is this my roof over my firewall?

2.

If I remember correctly, a firewall will have to be around 1 meter above the roof line.

i cannot actually get this ... because i thought that roofs are always above the firewall... i mean the roof ends where the firewall begins?

thanks

Re: Firewall waterproofing dilemma - is their a solution at all?

sir,
try using BOYSEN PLEXIBOND, and finish it with ELASTROMERIC PAINTS

Re: Firewall waterproofing dilemma - is their a solution at all?

A firewall is used when your house is built all the way to the property line. Then you need a fire wall that goes higher than your house, to prevent a fire from spreading from house to house.

The wall roof intersection is where your roof meets the firewall, which should be higher than your roof.

Hope this answers your question.

Re: Firewall waterproofing dilemma - is their a solution at all?

the rainy season is upon us again.

i live in a townhouse row. being the last unit in the row, i have this huge firewall which after several waterproofing treatments, never fail to leak rainwater through the wall after a heavy downpour.

the leak is not really like a waterfall, na parang 'tumatagas'. it's like drops of water that runs down from the ceiling down to the floor. also you can see bubbles of water forming under the paint.

it's not really much of a problem, except that i cannot have the wall painted because of this problem...

can i do something to finally stop this problem? or shal i just 'grin and bear it'?

thanks! great website here!

I have a newly built house and ang right side of the house was firewalled using 6" CHB plaster with Sahara back to back of the wall. Naka concrete gutter din ang buong right side. So far wait pa ako ng possible leaks since evry afternoon til night malakas ang ulan sa lugar namin.

What I did was I make sure na na-reach ang 15 days concrete curing bago ang painting ng wall. Sa exterior, ginamitan ko ng ruberized paint while sa interior naman ay basic latex with masilya lang. Yan ang problema kung hindi pa cure ang wall bago sila nag paint, malaki nga ang chance na mag leak yan. Lalu na kung ang ginamit na base paint is not for exterior and dapat pang waterproof ;D

Re: Firewall waterproofing dilemma - is their a solution at all?

i agree with 2diy4, sometimes its not the wall that leaks, instead its the flashing, a flashing is a g.i sheet bended to cover tha gaps between the wall and roof. That is the wall roof intersection.

Now, using an elastomeric paint will cover the tiny cracks on the firewall and thus sealing water form going in, as i have normally encountered on my projects, the roof wall intersection is always the culprit.

if the firewall has leaks on it you can notice it that the interior paint will have bubbles and and will have chicharon like texture and its moist. then your problem is the firewall.

Re: Firewall waterproofing dilemma - is their a solution at all?

You said you are the last unit of the townhouse and probably the source of leak is the firewall facing the other lot. If there is a G.I flashing, the outer length might not be of sufficient length to cover the source of leak that is penetrating the outer-wall (even if this is painted). Try extending down the flashing a little more (if this is aesthetically feasible).

Re: Firewall waterproofing dilemma - is their a solution at all?

the rainy season is upon us again.

i live in a townhouse row. being the last unit in the row, i have this huge firewall which after several waterproofing treatments, never fail to leak rainwater through the wall after a heavy downpour.

the leak is not really like a waterfall, na parang 'tumatagas'. it's like drops of water that runs down from the ceiling down to the floor. also you can see bubbles of water forming under the paint.

it's not really much of a problem, except that i cannot have the wall painted because of this problem...

can i do something to finally stop this problem? or shal i just 'grin and bear it'?

thanks! great website here!

If it still persists, I suggest you use Toroseal(cement based-brush) and Toroplug for holes, cracks and fissures on the wall. Other waterproofing materials such as elastomeric paints are also effective but they don't last long since it cracks when exposed to extreme weather conditions.

Re: Firewall waterproofing dilemma - is their a solution at all?

You said after several waterproofing treatments, your wall never failed to leak rainwater through the wall after a heavy downpour. First, I want to know who did the waterproofing treatments ? Were they licensed waterproofers ? What materials did they use ? What method of treatment did they apply ? As a waterproofer for 22 years, I have done a number of cases that point to the one being experienced by you. Your wall gets filled with water entering through the capillary tracks present in all concrete strata coupled by horizontal hairline cracks that catch hundreds of liters of water during a heavy downpour. Unless you treat your wall the proper way, your problem will remain until all the reinforcing bars inside your wall get corroded. I advise you not to buy those advertisements being peddled by paint manufacturers for they have nothing to offer in the solution of your problem. Get the services of professional and experienced waterproofers for they have an array of imported and tested materials to offer.

Re: Firewall waterproofing dilemma - is their a solution at all?

I agree. The problem is the wall face. With the paint having bubbles like chicharon proves that your wall is porous. Rain water penetrates the chb wall and finds its way to the internal face of the wall manifesting itself as bubbles in the paint. An asphalt based membrane type of waterproofing is the way to go or brushed on Polyurethane waterproofing. But this is quite expensive. Is the entire wall affected meaning from ground to third floor or only the top floor?

Re: Firewall waterproofing dilemma - is their a solution at all?

I bought a 10 year old house with asphalt shingle roofing. The roof also seems to be leaking at the firewall-roof intersection. Will adding GI flashing stop the leak in the roof? Will GI flashing work with asphalt shingles? If not, do you know roofing experts with experience in repairing asphalt shingle roofs? There aren't many houses with asphalt shingle roofs in the Philippines.

Thanks for the help.

Re: Firewall waterproofing dilemma - is their a solution at all?

I think that GI flashing will work with asphalt shingles. In the US, flashing is woven into the asphalt shingles while it is being laid, ensuring waterproofing.

But for a roof that is already laid up, the flashing will have to be laid on top of the asphalt shingles. But for this to work properly, some things have to be considered.

First the slope of the roof. How far the flashing extends on the roof will depend on the slope. The lower the slope, the greater the extension. Asphalt shingles don't work well with slopes greater than 1:4, or 1 unite rise for every 4 units run.

Second, the flashing will have to ensure that no water runs between the flashing and the fire wall. The most secure way to do this is to ensure that the flashing rises beyond the top of the firewall, and is then bent over the top of the firewall. Some people just cut a groove on the firewall, and then put a lip on the flashing that is inserted into the lip. The whole is then sealed with asphalt cement or silicone. But there will be a tendency for the water to seep through.

Finally, I will not nail the flashing onto the asphalt shingle roof. The flashing will have to be secured properly to the firewall. Tek screws with neoprene gaskets screwed onto tox anchors will probably be the most secure and waterproof. The flashing can be cemented to the roof with some special asphalt sealants used by shingle installers.

Who can do this? Suppliers of asphalt shingles have installers tht can help you. Good luck.

Re: Firewall waterproofing dilemma - is their a solution at all?

I found out that using Flexseal elastomeric paint is the best solution for your waterproofing problem. I have 20 years experience in waterproofing and have used Flexseal since early 90's and found out that they are the only elastomeric that really works here in the Philippines.

Not to say Ive not tried the new elastomeric paints in the market today like sun n rain and rain n shine, they both are lousy at waterproofing. This you may confirm yourself - try buying a quart of sun n rain and paint it on a concrete panel. After drying, put just a little bit of water on top of it - i guarantee you that bubbles and blister will form in about less than 5 mins. The other elastomeric rain n shine naman is just a latex paint packaged as an elastomeric coz no.1 - it is really flat (ask any paint company they will say that flats are latex), 2 - it doesnt waterproof (try putting it on a shoebox interior and fill it up with water, i guarantee you not only leaks but water pours down all over!).

I advise you to put in at least 3 coatings of flexseal on your firewall and your problem will disappear and the colors will last you for a long time.

Re: Firewall waterproofing dilemma - is their a solution at all?

experienced this leak during downpour of typoon "ONDOY" pero sa 2nd floor
firewall side lang yung sa 1st at attic ay pala pong tulo. sa cracks lang po
kaya ang problem?

thanks!