Hi everybody,
I have a rowhouse built on concrete slab, with the neighboring walls being CMU and the front and back sides brick. The house is built in the 50’s and completely lacks insulation as you can see in the picture, taken after plaster/drywall has been removed. The boards were nailed directly to wood that in turn were nailed to the brick with shims as separators. I have some concerns and would really appreciate your feedback and suggestions here:
– The brick wall (is it still called veneer when it’s structural?) goes below grade on the outside and seems to lack flashing. The concrete slab goes all the way to the brick so if there is an expansion joint in between, it has been covered in mortar.
– The brick is double thick except for a 2.5 feet section where a previous door has been removed and the wall i set with a single layer of brick.
– The plaster was soft and mushy the lower feet against the floor so moisture obviously becomes trapped and the shims are soft. As I understand, according to code, the wall should have atleast 1″ airspace and be connected to the brick by metal connectors. There wasn’t any felt paper or similar barrier either.
To get the comments started I guess I’m wondering if this was a common way of doing it, or perhaps I’m missing something here? What would you suggest, can flashing be inserted afterwards? Brick goes about a foot under grade until what looks like tar-painter footing, but I can’t see any weep holes. What would you suggest for insulation material and what could I use as a distanser for the airspace, some sort of plastic distancer and concrete screws?
Sorry for the ranting, but I’m really lost here. The way it’s done just doesn’t make sense to me.
Best regards
Nick
Replies
Welcome to BT nick... Here are my thoughts:
The boards were nailed directly to wood that in turn were nailed to the brick with shims as separators. - OK, so the interior finish was mounted on furring strips...
is it still called veneer when it's structural no, it is solid masonry construction
The brick is double thick It's called double withe (sp?) Basically your house is built like a brick $h!t house (literally) but needs some updating...
As I understand, according to code, the wall should have at least 1" airspace and be connected to the brick by metal connectors. There wasn't any felt paper or similar barrier either. You are getting "brick veneer" construction confused with solid masonry construction which is what you have. In a brick veneer structure, the metal brick ties help hold the veneer in place, since the house frame (wood studs) is the structural part - this is not the type of construction you have.
can flashing be inserted afterwards? I'm not sure what you want to flash. Generally the flashing I think you are referring to is for brick veneer structures.
Re the expantion joint, don't worry about that - it's way too late and won't help you now.
So, generally you are having moisture problems, and what to know is how to correct that and insulate the walls.
Here is a couple of things to get you started -
1st, your masonry walls will never be completly waterproof, so don't plan on it, but does the exterior need some "attention"? Do the mortar joints need to be tuckpointed? Ie: is there missing mortar between the bricks on the outside of the house? Are there parapet walls at the top of the walls between your and the next unit where the roof joins into a wall that separates yours with the next unit. If there are parapet walls, is the top of them properly water proofed? An overall pic of the house might help here. Or, are there other roof leaks that are allowing rain water into the walls? What about the windows and doors? Are there subtle leaks there? Hows the caulking around them? BTW - never use cheap caulk for exterior applications.
Is the grading around the building such that water is draining away from the house effectively? Is the soil around the house perpetually soaked? Are there down spouts that are dumping roof water directly at your foundation? Does the soil need to be pulled away from the masonry house and a damp proofing applied all the way from the footer to just below the finished grade?
Re the inside, basically what you want to do (after addressing all possible outside issues) is install a vaporer barrier against the walls, and build stud walls with PT bottom plates inside. These walls are non load bearing and are spaced slightly out from the wall. These can be mostly attached just at the ceiling and the floor. Since you already have moisture concerns, you might want to install a product called sill seal - it's a roll of thin foam - below the walls to keep water from wicking up through the concrete. It is cheap enough. Then you can install insulation between the stud bays. No vapor barrier on the insulation - either side. This is going to cost you floor space though. Another method would be to install VB, PT furring strips (again) fill between them with rigid insulation, then apply your interior finish. Make sure your interior finishes (sheetrock or whatever) don't touch the concrete floor - space them up just a little. Might even be best to fur the side walls and do the stud walls on the front and back - I'm assuming your unit has a adjoining (and touching) unit on either side. Basically, just think of it like finishing off a basement. You might even want to apply an interior basement waterproofing coating to the masonry walls before doing the interior work - Drylock is one.
Edited 7/25/2005 8:10 am ET by Matt
Edited 7/25/2005 8:17 am ET by Matt
Matt,Huge thanks for your reply, I can't begin to tell you how useful this info was. A couple of follow-ups:I'm probably a bit thick-headed here, but why isn't flashing and weep holes needed when the wall is structural? Won't water still sipher through to the inside or is the difference in the 2 wythes of brick? Sounds like moisture would stop at the slab?It also sounds like I still need some distance between the vapor barrier (can I use an adhesive against the brick for the VB?) and the insulation, even if it's rigid? I assume you mean something like Styrofoam here?I've enclosed a new picture where the previous door part can be seen. This section is only single wythe, does that mean that part will breathe more water? The lowest brick closest to the slab here is moist since tonight's rain, and there is a big gap/joint between it and the slab. The wall seems intact and looks ok on the outside.Can I isolate this door part the same way, which would create a huge air gap, or should I fill with cinter blocks/brick?Drylock sounds very tempting, I assume it would replace the VB, but could I screw rigid insulation and wood cleats on it directly?Again, sincere thanks for the help so far. Nick
Really I build new homes... At this point I'm going to let some of the remodeling guys jump in here...
Matt
While hoping for some further great insight from the forum I'm enclosing another picture, a close up of the door part I'm worried over. Here it can be seen that the lower brick row seems moist, I suspect this is the original base for the door and it's about at grade level.You can also see the gap between the brick and the slab. I can get my hand in there and feel the underside of the slab, so the foundation footing is way further down, which means that there is a big opening to the soil beneath, not to mention insects and other undesired guests. What can I do about it? Is this gap a necessary expansion joint or can I fill it with concrete? Better with a back rod and a sealer?Best regards
Nick
Come on, isn't there anyone who has an idea or suggestion on what I should do to isolate the wall, and if I can fill the crack and still sleep?Or are the questions to stupid?
bump
Thanks for the bump.I think I'm going to try structuring my questions a bit differently though, to make it easier to respond in parts instead. Please have a look at the pictures above.1) I've read up on solid masonry construction, but honestly still can't see why a single wythe let's through so much water that you need an airspace, flashing, and weep holes, whereas double wythe let's you nail wood furring or insulation foam directly against the brick? Looking in "Architectural Graphic Standards", they seem to feel you would be well off with flashing on double wythe load-bearing walls as well. Can anyone enlighten me here?2) Setting aside my wonderings above for a moment, can I place cell foam (I'm thinking of 1" Foamular with an R of 5) directly on the wall with adhesive, and then place PT furring strips on top with masonry screws, for the drywall? Better the other way around, strips against the brick and gypsum directly against the foam? DryLok seems to be a great vapor retarder (should I go for the Latex or oil version?), is it better than a bituminous sealer? Outside drainage and slope has been dramatically improved. Matt mentioned above that I shouldn't let the drywall go all the way to the floor to avoid moisture, but won't the baseboard take the hit instead then? I'm considering to polish the slab as floor for a original and contemporary look.At this point I need to mention that I've had a pretty serious termite issue and treated the soil perimiter with Termidor. I've read that cell foam can be a less good choice if termites are a concern.3) The area where there previously were a door is made up of single wythe brick, can I use a double layer cell foam there to compensate, or do I need to patch up to two layer of brick?4) As you can see on the pictures there are some big gaps between the concrete slab and the wall, in particular where the door was. Now can I fill this up with concrete or do I need some more flexible sealant? There seem to be an expansion joint that is partially covered with mortar along between the slab and the wall. I'm thinking of thick back rod and a Sika sealant here, but if the flexibility isn't crucial, I would prefer something stronger for longevity. Would something like Quickrete Patcher or DryLok Fast Plug be comparable to concrete in practice?Ok, still amounted to quite a handful but hopefully some of all the experienced forum people here can find a moment to help me out.Nick
Not a single feedback?
Man, I'm sorry you're not getting very many responses. I'm not at all knowledgeable about brick, so don't feel qualified to say much. Maybe this will push you back near the top and others will respond. Sounds to me though, that your questions are making us think you'd be well advised to get a professional to get out there and look at it in person. Lots going on that is hard to deal with at a distance. The first poster had good ideas and good questions. If you post answers to those, others may be more willing to talk to you. Exposing the below-grade brick and waterproofing it, then making sure there is adequate drainage would help a great deal. Making sure you have stopped the sources of water infiltration is another important first step. Once the water is mitigated, you can address the other issues.
Mmmm, nasty picture.....
If you can actually get your fingers through that crack & feel the underside of the slab, you've got problems.....since if you can, you aren't feeling compacted stone, a vapor barrier, or a sump drain....
IMHO, brick just plain doesn't belong underground...if it were my house, I'd be digging outside to find out where I what the footer is....if the footer's good, then I'd be parging & waterproofing up to above grade, & then I'd start worrying about the permeability of a one vs two wythe brick wall....
Thanks for the responses, good to see someone is out there. Danno, the first poster was indeed extremely useful, and I'm more or less basing the follow-ups on that one. I'm honestly still curious to why a brick veneer needs flashing and airspace, whereas solid masonry do not, especially since I have a 3 feet wide section where my wall is single layer brick. However, setting that aside I'm going to make my questions/concerns even more straight forward:Drainage has been improved, concrete brick patio removed and will be replaced with 4" gravel sloping away from house. 1) I've digged around the perimeter and there are two rows of brick under grade and then what looks like CMU. Matt mentioned a damp proofing but I don't want to put rigid foamboard on the outside since there is a termite history. Any suggestions, some sort of bituminous sealer? Will DryLok work on external surfaces? Just let it be?2) I want to fill the expansion joint between the brick wall and the slab. It's about an inch wide and filled with soil, an entrance to the house for termites etc. Should I use back rod/some sort of sealant or can I use concrete or something like DryLok Fast Plug? I'm afraid that a hard seal may damage the brick if the slab expands/contracts?3) Based on Matt's advice I'm planning to insulate the inside of the external brick wall by painting it with DryLok Masonry Waterproofer on the inside, screwing on PT wood furring with concrete screws, nailing 1" InsuPINK (rigid foamboard) and then nailing 1/2" gypsum. It would be problematic space-wise to install studs. Will Drylok be enough as a vapor retarder?4) Matt also mentioned that the finishes shouldn't touch the floor. Does this apply for the rigid foamboard as well? Won't that create a thermo leak/draft?I'm really not as ambivalent as it sounds, I'm just looking for some experienced confirmation and possibly added light. Isn't that what the forum is about?Nick